When the Autobots are forced to leave Earth, there are said to be nine of them. However, at this point in the movie there are eleven: Optimus, Bumblebee, Ratchet, Sideswipe, Dino, Que, the three Wreckers, Wheelie and Brains. However, Wheelie and Brains had been hiding on Earth in Sam's apartment and were not part of NEST's "inventory".
In the flashback scene of the Apollo launch, the American Flag and NASA logo can be seen on the Vehicle Assembly Building. The flag was not painted till 1976 in celebration of the United States Bicentennial celebrations. The NASA logo was added in 1998 in celebration of their 40th anniversary, replacing the bicentennial emblem.
When Simmons is searching the Chernobyl site for alien technology, he comes across a box with an "Intercosmos" logo printed on it, which he then says "dates back to Sputnik." Intercosmos was a Russian organization that included cosmonauts from other countries on Soviet space flights. However, Intercosmos existed between 1978 and 1988; Sputnik was launched in 1957, twenty-one years earlier.
In the opening scene set in 1961, when government officials race to the White House in two black Lincoln Continentals, one Lincoln is period correct, but the other is clearly a 1965 or later model as noted by the squared-off front grille.
In the opening scenes, a flashback to 1961 is shown in which an office appears with several spacecraft and rocket models in the background. One is the Saturn V rocket, which was yet to be designed and made in 1961, in the early days of American manned spaceflight.
When Carly is first brought to Chicago, she has straight hair, light shirt, and white jacket. When Sam rescues her, her outfit has changed and her hair is now wavy. Her clothes continuously change throughout the movie during long scenes when she would have no way to switch outfits.
In the start of the movie when Sam is holding Brains, the small robot, looking for a box to put him in, a shot of Carly shows Sam in the background holding his arm out with nothing in it. In the next shot the robot reappears and Sam puts it in the box he has found.
When Sam and Dylan are fighting on top of some rubble, the clock on the building behind them changes time from scene to scene. In the first shot it's 10:40h, in the next 1:00h and in the last shot 11:05h.
During the highway chase scene, the running Decepticons flip a silver Saturn Outlook, a silver Nissan Altima and then a black Chevy Trailblazer in that order. During the next shot, from a different angle, the footage is reused and the same cars flip over again in the same order.
When Sam and his allies survive a slide down a dwindling building that is almost split in half, they appear near the bottom of the separating top half. Once Shockwave's driller is sent to destroy the building in an attempt to eliminate the survivors, the building falls against a nearby apartment complex. The survivors are seen moving across to this new structure. However, to move to the next building, they are again seen at the highest part of the building, regardless of the slide that placed them near the bottom.
On the bridge, when Sam and Carly kiss, her right hand is positioned on Sam's face and is dirty, particularly the thumb. The next scene her right hand is behind his head and is clean. It alternates throughout the entire scene.
At the end of the battle on the bridge, Ratchet and Bumblebee are shown to be identical in height as Ratchet commends Bumblebee for his bravery, but seconds before as Ratchet, Bumblebee and Sideswipe approach from a wider angle, Ratchet is clearly 5-6 foot taller then Bumblebee and Sideswipe.
In the aerial shot of Optimus Prime flying into the battle in Chicago, we see Ratchet, Bumblebee and Sideswipe advance firing. From behind Prime we can see Brawl is quite a distance from the fire truck which Sideswipe is taking cover behind. However, as Prime lands, Brawl is the first Decepticon slaughtered by him as he knocks him over.
When Sentinel reveals his deal with Megatron and kills Ironhide, his rusting gun changes sides back and forth. When he shoots Ironhide for the first time it's on his right hand, the second time it's on his left. When he starts shooting randomly to the NEST team and the headquarters, it is on his right hand, and while he transforms into his alternate mode he is shooting with his left hand.
When Carly is talking to Sam by the car before Dylan's party, there is a shot, when Sideswipe and Dino pull up behind the Mercedes. In the next shot, Dino is on the other side of the street, then, in the next shot, neither Sideswipe nor Dino are in the street.
When the Decepticon scans the Waste Management truck in Washington, DC, it is apparent that he is not in his protoform like all the other troops. He is already in his bipedal Earth form before he has successfully scanned an Earth vehicle.
During Sam's flashback of receiving his medal from the President, Sam's hair is parted on the RIGHT Side of his head yet when he meets Carly, a very short time later, his hair is parted on the LEFT Side of his head.
While the opening scenes of the listening post are captioned as occurring in 1961, the urgent teletype message that is sent reporting the lunar impact that they have detected that day is datestamped July 10, 1962. ("7-10-62") In addition, an entire third line of text is seen being printed in closeup ("CONTACT AT 2250 GMT") prior to the END line, but is missing from the paper when it's torn off the printer in the very next shot. While the END line is still visible, the entire CONTACT line above it has disappeared.
When the skyscraper falls over and onto the building next door Carly falls onto the other building. In earlier shots you can see the other building is of modern concrete and glass construction but when she falls across she stands against a bricks and mortar wall with older design tenement windows.
When Sam and Carly are talking in the conference room, Sam stops setting out the folders to look up something on the computer. In the rest of the scene, the folders to Sam's right change from not being passed out, to placed in front of chairs, and back again.
Carly's shoes appear to mysteriously alternate several times between black stiletto heels and black ballet flats in-between shots during the climactic action sequence. This is most noticeable during the collapsing building sequence as well as the scene in which Carly speaks to Megatron.
In the scene with Richard Nixon speaking to the Apollo astronauts, the TV showing the phone call shows a lamp behind his head, and the seat being right behind him. But if you look at the actor sat there, there is no lamp, and the angle of the camera shows the chair would not be in shot.
When they all slide down the building, we get a shot that pans up. In this shot, Sam is the one closest to the bottom of the building and Carly is one of the people on the very top. Yet in the next shot, Sam catches up with Carly.
In the scene where Sam, Carly and others slide down the collapsing building, the shot from above reveals only one window hole where they could have jumped from, and Sam and Carly are sliding quite far off to the side from the hole.
When Ironhide and Sideswipe confront the Dreads all four drop their guns on the ground, yet minutes later when Iornhide is hit by a spear it immediately shows his guns back on his back. Then when Ironhide catches Sideswipe's gun, his rifles are no longer on his back.
After Cybertron is pulled into Earth's orbit, they show that it can be seen from the earth's surface, pretty much the entire sky is taken up with Cybertron. However, in several scenes afterwards the sky is shown in the background as being crystal clear again.
When Optimus takes a dive after his rampage in front of Shockwave, you can see that it is actually in front of the building with the control pillar in it (note the very distinct clock in the background) yet when Optimus shoots the dome and the pillar down, he's a good distance away from it.
After Ironhide crashes into the remaining Dreads, we see that Crowbar lands on a bus stop, but when Sideswipe arrives, he is in front of an open garage door, at least 10 ft. away from the bus stop, debris is nowhere to be seen.
In the highway chase scene, one of the Decepticons knocks down the freeway sign which causes the signs, originally facing the on coming cars, to flip away from them. The other two Decpticons then use the signs to as a ramp to get further down the road. This should be impossible because the signs didn't land that way. When the Decepticons land, the signs are pointing the first way again.
After Ironhide crashes into the two remaining Dreads, both of them transform. We get a close-up of one of them, who transforms over a lamppost, about 10 feet above it. The next shot has him past the lamppost, and at the same height as the lantern itself - instantly.
When Sam and Jerry Wang are in the elevator, just after the other co-workers leave, Jerry takes a drink from his milk carton, placing the straw in his mouth, from the top of the straw, down to the hinge section. The shot cuts and there is suddenly less of the straw in his mouth.
During the final fight between Optimus and Sentinel, a long curved copper pipe going from Sentinel Prime's chest to his right arm disappears and reappears between shots. And it isn't torn of in the fight between only the Prime's, I cannot say if Megatron doesn't remove it later on.
Sideswipe's rims keep changing throughout the movie. At some point he has rims which have a pretty big distance between the edge and the actual spokes and at other points he has rims which have the spokes on the edge of the wheels all together.
During the freeway chase, there is a shot with Hatchet landing on a car on the opposite side of the freeway. This shot has all sorts of poles on the center guardrail, and structures in the background. Then the poles in the center disappear, and the white-ish buildings in the background change into a bridge.
When the Autobots return from their fake deaths, Optimus shoots down an enemy ship by destroying the right turbine, making it crash down and saving Sam. But later on, Bumblebee starts it up and flies it with no apparent damage.
In the Chicago battle, when Sam and Carly are hiding behind the school bus he says, "He's after me, not you... run," and she stands up to start running, her shoes are no longer black (heels or flats) they're white.
When Starscream flies in to destroy the Ospreys with Lennox and his team, you can see that the streets below are pretty badly damaged. When the soldiers jump, there are a few shots from a helmet cam from one of the soldiers and the streets are completely intact.
When Sideswipe kicks the gun towards Ironhide, the latter one catches, turns, locks, aims and holds the gun still all in the same motion. The nest shot has him do the same again, only this time he keeps on turning.
When Optimus dives in front of Shockwave, there is all sorts of rubble around the latter one. In the shot of the bullet arriving at the cupola, all of the rubble, damage to the street and broken cars are gone.
In the scene when the characters are sliding down the glass building, just before they shoot the windows, there is a shot where a chair is sliding down along them on the left side. The camera dips down for a moment, and when it goes back up, the chair is gone, even though there is no hole in the building for it to go.
During the Mexican Standoff, Ironhide finally forces the spike into the face of one of the Dreads and lifts him up by it. Pay attention to the red car underneath: when Ironhide smashes the Decepticon's face, the windshield is fine, but when he puts him down, the windshield is suddenly damaged - before the Decepticon lands.
Just before the soldiers jump out of the Osprey, there is a shot of them running for the exit. You can see a very big gun on the soldier's chest. But in every shot of them wingsuiting through Chicago, none of the soldiers can be seen carrying any kind of weapons, let alone big LMG's and assault rifles which they use after landing.
When Optimus takes the roll to avoid getting shot by Shockwave, you can see the very distinct clock of the Hotchkiss building can be seen in the background, yet they aren't fighting in front of that. In the next shots, the building in front of which Optimus rips out Shockwave's eye is much more modern.
When Carly nearly reaches Megatron, there is a slow-motion shot of her with an SUV blowing up in the background. In the first shot, it flies up in an upright position. In the second shot, it suddenly spinning.
When Crowbar dropped his weapons in the ''Mexican stand-off'' we get a look at his ''dread locks''. When he pulls the spike which he throws at Ironhide, the locks disappear, only to return in the subsequent shots.
When Charlotte Mearing, the United States Director of National Intelligence is talking to Optimus Prime about the teleportation device, the position of her hands on the red hand rail differs between shots.
In the scene where Sam and Carly are trying to get into the Autobot base, Carly is wearing a black jacket, after Sam sees Bumblebee, she is wearing a brown one, and inside she has a black one on again.
When Ironhide crashes into the remaining dreads and transforms, one of the dreads is shown falling into some kind of wooden box covered with glass breaking it apart. In the next shot the Decepticon stands up and the debris is not visible.
After Optimus rips Megatron's head and spine out, he drops it right next to Megatron's dead body. But when Sam and Carly are reunited, the head with the axe lodged in it are much further away from Megatron.
Just before Optimus Prime arrives in the street where he kills ten Decepticons in twenty seconds, there is a shot of Sentinel saying "It's our world now!", and he is looking out over that same street. When Sam comes out of cover to take a look at Cybertron, Sentinel is still on the building. But when Sam shouts "Optimus!" Sentinel is gone.
After Optimus saves the day by shooting the Decepticon hovercraft, we get a small speech. When he says: ''For today, in the name of freedom'', his gun disappears. We never hear him throw it away, or see it lying around when Bumblebee transforms.
When Sam's parents first show up, we see a shot of their RV with a car parked behind it, on the pavement. When they go to use this car to take him to his interviews it is now on a trailer behind the RV.
In the NASA radio room, There are two men standing beside a cabinet. One a white shirt and tie, the other in a full suit. When the shot cuts, they have instantly switched sides, and the one who doesn't wear a jacket, suddenly is wearing glasses.
When Sam is interviewed by Bruce Brazos there is a glass sphere on the desk, showing the reflection of the cameraman in the bottom left hand corner of the shot. The cameraman is visible throughout this scene.
For most of the scenes set in Washington DC, the main characters are seen in a city of skyscrapers well over 30 floors high. However, in the real Washington DC, only two structures are taller than the US Capitol Builing, and there are no skyscrapers in the city. The large slanted building in the background is actually the Smurfit-Stone Building in Chicago. (There are no building in DC higher than the Capital building by elevation. The Capital is the highest by law, no building or structure can be higher than it. A building can be taller by floors but not by elevation.)
After the sign 'Chernobyl' is seen Polissya hotel which is in abandoned Pripyat city (as the big wheel), not in Chernobyl town. The damaged reactor is approximately 3 km away from the city and the other side.
Shia LaBeouf's character is seen living in an apartment in Washington D.C. In various scenes where he is outside in the back alley, you can tell there are skyscrapers. However, there are no skyscrapers near Washington D.C.
During the freeway attack outside Washington, D.C., one of the signs that is destroyed reads "West Interstate 88, Aurora". That portion of Interstate 88 runs from the western suburbs of Chicago to the Iowa border, and is nowhere near D.C.
During the freeway attack outside Washington, D.C., one of the overhead freeway signs that is destroyed reads "Business Route 20, State Street". That sign corresponds to an Interstate's 39 & 90 exit at Rockford Illinois. U.S. Route 20 runs across the northern United States, nowhere near Washington, D.C..
In the slow-motion wing-suit scene in Chicago when the men are seen jumping out of the aircraft, the backdrop image shows a reversed/flipped image of Chicago, with notable landmarks such as the Aon Center being located north of the Hancock building, rather than south.
At the beginning of the Chernobyl scene, one of the Russians clearly states that Chernobyl will not be inhabitable for 20,000 years. Chernobyl, Prypriat, and surrounding areas will in fact be uninhabitable for about 200 to 300 years. This area is contaminated primarily with Strontium 90 and Caesium 137, both of which have half lives of about 30 years. Most scientists agree that it will take about 10 half life iterations for radiation to return to the background levels before the accident, which would be a time frame of around 300 years. Some people still live in Chernobyl and short term tours are offered in Prypriat. In most places within the city, the level of radiation does not exceed an equivalent dose of one microsievert per hour.
When the Autobots visit the moon, the original Apollo 11 moon lander is shown with the ascent stage (the upper part) still attached. The ascent stage was used to return the crew into lunar orbit, so only the descent stage (lower part) should be still there.
Sam is heard to say that the lunar farside is the same as the lunar dark side. As the moon is tidally locked (ie. rotates in sync) with the earth, it shows the same face to earth at all times. As the moon revolves around the earth, the lunar farside revolves into sun light and back into shadow, this is said to be the phases of the moon. The only time that all of the lunar farside can said to be the lunar dark side is during the full moon. At all other times part or all (during the new moon) of the lunar farside gets some degree of sun light.
The film depicts Neil Armstrong's first step on the moon as the moment when he hops from the ladder. During the actual Apollo 11 moon landing, Neil Armstrong jumped onto the bottom of the ladder and then slowly placed his left foot (the film depicts his right) onto the lunar surface.
When Simmons encrypts the phone call, no decryption system is set up on the other end of the phone call. Due to the way encryption works, the other end of the call must be able to decrypt the message, otherwise all they would hear is gibberish.
In the Apollo 11 scene, the Flight Director says "EGIL, get that signal back." There was NO EGIL flight controller position back then. It was all under EECOM. If he wanted communications back he would have yelled at INCO (Integrated Communications Officer).
As the Ark is on the far side of the moon, Earth shouldn't be visible from there, but while the astronauts approach it to investigate a "cresent Earth", it is clearly visible on the top-right hand side of the frame.
When Soundwave prepares to execute Bumblebee, his gun charges up and reveals an orange interior but when he begins firing after the ships drop the projectile is a dark blue indicating that his weapon is a sonic cannon and not a plasma cannon. There is no rule that states he cannot switch between the two types of cannons.
After Sam and Carly exit Bumblebee in the streets of Chicago, as they run towards the bus stop there is a quick shot of a green hummer h2. This is Ratchet's alternate mode, despite Ratchet having already transformed. Despite this, there's no reason there can't be another truck like that nearby.
When Sam is speaking to the UAV drone he says that the Decepticons are transporting Cybertron to Earth. But Carly was the only one at that point to have known about this from Dylan, so how did Sam know this, when he was on top of the cruiser fighting Laserbeak when Carly was in the cockpit with Bumblebee? That question is easily answered. How long does it take to say "Sentinel's bringing Cybertron here!"
The character Dutch, despite his name suggesting otherwise, appears to be German, as he has a few lines in this language. However, in the stand-off scene in the Russian bar Simmons shouts at Dutch in a different language, that appears to be part German and part gibberish.
Also, the nickname "Dutch" has long been used for people of German background, mainly being a mispronunciation of what Germans call themselves - Deutsch.
When the Ark lands on the moon in the beginning, the impact causes fire. Fire needs oxygen. There is no oxygen on the moon, therefore there can't be fire. Most spacecraft (of earth design) require an oxidizer component to the fuel mixture, it is not out of the question for an Autobot designed spacecraft to also need an oxidizer. Therefore it is possible that an oxidizer tank could have ruptured when crashing and thus allowed fire on the moon, but just till the oxidizer was used up.
When Megatron destroys the Lincoln statue and sits down on it the wheel on his left feet appears to be seen going through the steps. However, on the actual memorial, Lincoln's feet are sitting on top of an elevated platform above the base. Megatron's feet are straddling that elevated platform making it appear like his CGI model is going through the base, when it really is not.
The loss of signal depicted in the movie caused by the Apollo 11 lunar spacecraft being on the "dark side of the moon" is incorrect. The moon rotates and orbits the earth at the same rate so the same side of the moon always faces the earth and the dark side is never visible. The loss of signal depicted, with Walter Cronkite commenting, is actually from when the command module orbiting the moon would pass behind the moon from the earth making radio communication impossible. The landing site for Apollo 11 is located just to the right of center when looking at the moon and just north of the lunar equator, which means that it is nowhere near the far side. However, this is intended to be a NASA Black Op, and since it's shown in the movie that NASA can still communicate with the astronauts after the "signal loss" is announced, it's clear that the loss is intended to give them time to investigate without all of the U.S. listening in, and the general public (of the time) would be none the wiser.
When Sam has to go to the interview, his car doesn't start, so his parents give him a ride to the interview in their car. When after the interview, Sam and Carly leave the building, Sam's old car is parked outside. In that scene, the building seen is Carly's place of employment. It is entirely possible that after Sam's interview (at a different location) that he went home and got his car to meet with Carly at her place of employment.
Optimus Prime's mouthshield goes from flat to vented during some shots whilst fighting. The flat mouthshield is the most current version, whilst the vented mouthshield was used in the previous two films. Nothing says that his mouthshield needs to stay exactly the same as the previous two films.
When Sentinel Prime is shown in low power mode while in the Ark and prior to that in the opening sequence - he is shown to have red colouring and windscreen parts on his chest, parts that would be required for his alternate mode of a Rosenbauer Panther fire truck. Sentinel Prime never made it to Earth and would not have been able to scan a truck to give him this alternate mode therefore he should have appeared as a cybertronian protoform. It is entirely likely that he received the coloring as he was left for so long and that he was, in fact, given a vehicle to disguise as during his trip back to earth as he laid in low power.
It was stated by Que that the boom-sticks would arm in 30 seconds.While the one Sam used to kill Starscream no doubt took 30 seconds the ones the military used on Barricade and a protoform took even less time, about 3 seconds. This could very well be that Que left them easy to adjust the timer although Sam would never have known it given that he wasn't an official part of NEST.
When Optimus Prime merges the spark in Sentinel's chest, he immediately starts to speak after he is told he is safe. In the first film, the Transformers learned Earth language through the world wide web. Sentinel could not have been aware of this as he was in sleep mode since he crashed onto the moon, and, given he didn't know where he was, it was impossible to know how to speak English. However, an undetermined amount of time had passed between the moment Sentinel was retrieved and the moment he appears in the NEST base, and as Ratchet states, he was in low-power mode, so it's not entirely unreasonable to think that the Autobots might have uploaded language data to him while he was sleeping before reactivating him.
Towards the end of the movie, when the Autobots return to assist Sam and his fellows in taking back Chicago, one of the robots mentions that the Autobots were in the first booster rocket to separate. During the launch of the Autobot spacecraft, however, the booster rockets never separated before being blown up. As the ship was hit primarily in the main part and not in the boosters, it's entirely plausible that, even if they didn't "separate" at the time, their hiding place remained viable and splashed down as expected.
When Sam is being interviewed by Bruce Brazos, the man says Accuretta contracts for DARPA, NASA, and JPL. JPL is part of NASA, not its own entity. This is a common misconception as they are listed as two separate entities although one does work almost exclusively for the the other.
During the plot Megatron explains that his original intent of arriving to Earth was to meet up with Sentinel Prime rather then to claim the Allspark, however this is hard to believe considering Megatron crashed landed several hundred years before Sentinel's arrival in the 1960s. It's not unreasonable to assume that the massive damage to Sentinel's ship slowed him a lot and allowed Megatron to overtake him.
When we see Sentinel Prime being extracted from the Ark by Optimus, we can see that Sentinel Prime already looks the same way as he does throughout the rest of the movie. The Ark crash landed in the 1960's, the Rosenbauer Panther Fire Truck didn't exist in the form we see Sentinel Prime transform into. All of the other Autobots came to Earth in their proto forms and adopted a disguise when they arrived [we see them scanning alternate modes - one Decepticon is shown doing likewise in this movie]. Sentinel Prime already has his disguise when on the ark, which isn't possible.
The film tries to claim that all six lunar missions were to collect samples from the Ark. However, the missions had landing coordinates hundreds of miles apart. If only 35 people knew about the secret mission, that leaves hundreds of thousands of others who believed they were working toward actual lunar exploration, meaning it would be very difficult to fake telemetry data without someone noticing. Also, there are long range photographs of the different landing sites showing the landing craft at their true lunar landing spots.
In the scene where Sam and Carly are attempting to communicate to the military through the UAV drone, Sam tells them all about the Decepticons' plan to bring Cybertron into our atmosphere. But Sam was never there when Dylan explained the plan to Carly, and there was no time for Carly to have told him.
The film claims that the Ark crashed on the moon in the 1960's implying that Megatron was still waging war against the Autobots on Cybertron during this time. In the first Transformers it is stated that Megatron had been in cryo sleep at the Hoover Dam since 1935, which obviously makes this timeline impossible.
When the Autobots leave the earth to avoid war with Decepticons. Dylan Gould calls Sam Witwicky but when he places the phone near his ear, no call is actually made as you can clearly see the phone dialer is still visible in his phone screen.
When the Apollo spacecraft with LEM enters the moon's orbit, the scene was clearly "borrowed" from the movie Apollo 13. The Apollo spacecraft clearly has the panel missing, antenna array damage, and debris trailing behind it.
During the Russian bar scene, Dutch "pumps" the fore-grip of the breech-loading shotgun to chamber a new shell and eject the spent one. There's even the sound of the shell being ejected and hitting the floor, despite this being impossible for the type of gun he is using.
When showing Nixon giving his address, the image shown on the monitor was very similar to the view the audience gets. However, there is a lamp shade on the monitor that was nowhere visible in the room.
When the wreckers appear in Chicago you can clearly see them ripping a decepticon pilot apart. But once Optimus begins to explain to Sam and Epps how they survived you can see the wreckers are no longer behind them. Then after the other autobots appear all 3 wreckers are clearly visible again
After Starscream stops banging his head on the ground trying to get the boom stick out he clearly looks up at the camera and you can see for a brief second that his eye (which is supposed to have the hook in it) is clearly fine and intact.
During the scene where Bumblebee says goodbye to Sam, Bumblebee is leaning with his right arm to the construction. When the camera rotates, you clearly can see the his hand is moving through the structure, making it a flaw in the CGI.
When Megatron is about to destroy Lincolns stone throne, his shadow appears only in the shots where he is visible, but in the shot where only the throne is visible and Megatron is about to destroy it, his shadow is gone.
In the highway chase scene, when Crowbar knocks down some signs for the other two Dreads to use them as ramps, the simple structure supporting the signs changes to a far more elaborated one when the Decepticons launch from it. The signs are even replaced with actual platforms, much longer, wider, and with different angle and separation than in the previous shot.
Right after Sentinel finishes his speech at the tower, there is a shot where a lot of ships are shooting at buildings, but when they smoke from the explosions is gone, none of them is damaged. This mistake can also be seen when the dropped US soldiers are being chased and shot at by Decepticon ships.
Toward the end, when Sam is going to destroy the tower he gets kicked in the stomach by Dylan. When Sam falls he lands on another part of the destroyed building, you see the chunk of building that he lands on conform to his body, showing that it is made of foam to soften his landing.
When Optimus has his 'rage' on Wacker Drive, you can see that cars that are being flipped not entirely by volition, since some of them (most notably the red BMW before he cuts a Decepticon clean in half) aren't even touched by Optimus or any Decepticons.
When Dino (Mirage) throws Hatchet over to the other side of the freeway, Hatchet doesn't even make the security van right next to the car he crashes move, while he should have. His arm is basically going right through the van.
A Decepticon ship crashes into and destroys a fair amount of the Tribune Tower's steeple. Later, a wide shot of the city shows the Tribune Tower with white blocks composited on top of it. The animators forgot to put the damage into this shot.
During the highway chase scenes there are two "out of sync" animation sequences of the Decepticons in action. 1) In the front view with all the cars facing the camera, the Decepticon robot on the right shoves the car sideways (to the right), however, the car flies into the air a second later and in the opposite direction. 2) The scene cuts to the side view of the Decepticon and you see him motioning to pick up a car and begin to toss it in the air. However, when he does this, his hand is empty and the car just flies just below him.
In the Chicago battle scene when the two small autobots bring down the large decepticon ship, just after the ship runs into the building (Key Tower, Tribune Tower, or Pittsfield Building), the CGI detail is unrendered and the top of the building is only drawn in plain polygon.
The goof items below may give away important plot points.
Transporting a large planet into Earth's orbit would have devastating effects to the Earth's gravitational field and orbit around the sun. The Decepticons' plan to enslave humanity would fail as all or most of the Earth's population would be dead.
When Que is about to be executed by the Decepticons, you can briefly glimpse the "head on a stick" prop of Dino in the background. Originally, the scene called for Dino to be killed, but it was rewritten at the insistence of Ferrari (the car type Dino transforms into), however they forgot to digitally erase this prop out of the shot.