When Tony Stark is showing Yinsen the schematic for the Iron Man suit, you can clearly see the newly made mini arc reactor glowing in his shirt. Then in the next scene it shows them placing the one in he just made before that scene.
In the scene where Tony is upgrading the MkII suit to correct the icing problem, one of the screens behind him is taking a real-time transcript of his and Jarvis' dialogue. When Jarvis asks, "Shall I render using proposed specifications?", the computer screen says "utilizing" instead of "using."
Rhodey talks about UAV's as not having the experience or instinct of a pilot. In reality, UAV's are not completely autonomous, but piloted from a command area by a person and thus these arguments against UAV's are void. Rhodey would know this as it's commonly available knowledge.
In the sequence when the Air Force fighters try to shoot down Iron Man, LTC Rhodes calls the Air Force officer in charge of the ops center "Major" when the subdued rank on his uniform indicates that he is a Lieutenant Colonel.
A magazine cover announces that Tony Stark 'takes the reigns' at his company, rather than the correct 'reins'. While some people have suggested that this is a pun, there is no justification for such a word play in this context.
When Tony Stark drives his Audi R8 to Disney Hall for the benefit event, there is no front license plate affixed to the vehicle. However, when he pulls up to the entrance, his "STARK4" vanity plate is clearly visible on the front of the car.
When Tony Stark is being interviewed by Christine Everhart, his goatee is small, thin, and pointed, and his mustache appears almost drawn-on. The following morning, after seducing her, his goatee and mustache have grown, becoming round and full, in far too little time to be natural.
When Pepper brings a cup of coffee balanced on a brown paper wrapped parcel, the parcel is on its side (taped ends are horizontal, box is on its longer side). When Tony later moves the coffee mug and proceeds to unwrap the parcel, the taped ends are now at the top rather than the side (it's resting on its shorter side).
During the scene when Raza is threatening Yensin, he picks up all of the papers with designs for the Mark I and when he places them back, there are other papers sitting there as if he hadn't picked them all up.
In the opening scene where Tony Stark is in the "funvee" with AC/DC playing, drink in hand, there's some kind tape glue residue (like duct tape would leave) on his window that is inconsistently visible between shots.
While Stark is working on the flight stabilizers, Pepper brings down a box with a cup of coffee on top of it. Following that, Stark eventually goes upstairs, talks with Stane, comes back down, finishes the stabilizers, tests them, builds the entire prototype suit, test flies it, returns and picks the coffee up off the top of the box. Steam can be seen coming off the cup even though it's probably hours, if not days, old.
During the movie that Pepper's bangs vary in length. At the party, Pepper's bangs are short and fall just above her eyes. During the fight sequence while Pepper is with the government agents, her bangs are short and barely able to be pushed behind her ears. But the following day when she is helping Tony prepare for the press conference her hair is longer as if she never had bangs in the first place.
When Tony Stark escapes the terrorist camp by flying away in the first suit, he crash lands on his back with his head downhill and his feet uphill. But in the ensuing cut he is buried in the sand on his back with his head uphill and his feet downhill.
In the party scene when Tony Stark is buying a drink, he puts a folded bill in the tip glass, which can be seen sticking out from the rest. When it cuts to where you can see a close-up of the money glass, Tony's tip is no longer there.
When Iron Man saves the villagers and puts his fist through the wall to grab the last bad guy, he goes through the wall with his right fist over the guy's right shoulder. When he pulls the man back through the wall, Iron Man's right hand is now on the guy's left side as he pulls him backward.
When Stark is in the Afghani cave lab starting up his crude Iron Man armor, three guards come to the lab entrance. One guard advances into the darkened lab, and Stark knocks him across the lab. But when Stark in the armor walks around to the lab entrance, the original three guards are standing there instead of only two.
Stark falls off of one plane and another plane flies through him shearing off its left wing. The plane immediately starts a clockwise roll as if the right wing's weight would cause the right side of the plane to dip. In actuality the plane would roll counter clockwise because the only lift is from the right wing so it would rise.
In the beginning sequence when Tony Stark is in Afghanistan riding in a HMMWV without armor protection with several US Air Force Airmen. An up armored HMMWV's doors have very thick armor and glass. You can tell by looking at the blast holes in the side of the vehicle this is not an armored variant of the HMMWV. This is almost impossible. Months after the US military attacked Afghanistan a General Order was made that prohibited non up-armored HMMWV's from leaving any base camps. Certainly, if Tony Stark was traveling with the US military he would have been afforded the highest level of security.
In the opening scene a rocket is seen burrowing into the dirt next to Tony before exploding. The warhead is clearly blue and likely a Mk 153 SMAW round. Any munition in use with the military that is blue (such as the SMAW Common Practice Round) is used for the sole purpose of training and would therefore not explode.
In the craps game, Rhodey hits Tony's hand to throw the dice. They come up snake eyes and the croupier says "line away". He would only say that after a roll of seven that was made after a point was established, meaning everyone's pass line bet loses. For snake eyes he should have said "two craps".
When Rhodey holds the news conference announcing the unfortunate training exercise, his rank broadcast on Channel 3 KNKV News on-screen is "Col. James Rhodes". Verbally addressing him as Colonel Rhodes would be acceptable, but protocol would dictate his rank be displayed as "Lt Col" (Lieutenant Colonel).
Outside the press conference, Tony pulls one Burger King cheeseburger out of the bag Hogan is holding and is seen finishing it in the next scene when he is walking to the podium. But, when Tony is seated and begins talking about his father, he pulls the cheeseburger out of his pocket and begins eating it. When Stane asked if he had one for him, Stark replied that there was only one left, suggesting he bought more than one. In fact, he did buy more than one burger as he was finishing one when he was getting out of the car. There is a good chance that he placed one in his coat pocket before reaching for the last one in the bag. When Stane asked him if he had one for him he had one open in his hand getting ready to eat it and one in his pocket for eating later.
The Afghan people speak in Arabic which is wrong. In fact, Afghan people speak in Ordu, Pashtu and Farsi, not Arabic. However, Yinsen tells Tony that the group that captures him speak many different languages. So any Afghan people talking in a different language than their own is plausible.
When Yinsen asks Tony Stark about the first arc discharge reactors capacity, Stark gives it in gigajoules per second. From this Yinsen calculates that it could sustain his heart for fifty lifetimes. This deduction is impossible, as total running time of a device requires knowledge of total energy produced and not just instantaneous power which Joules per second describes. However, this is not a goof, as Yinsen may have seen some calculations of Stark's and with this new information, reached his conclusion.
When Tony reveals the power generation of the first arc reactor he uses in his chest, he gives it in gigajoules per second (more typically called gigawatts). Since the reactor is generating this much power, the amount of power available to the suit in the ending battle should not be dropping steadily, but should be constant until the reactor stops generating power. However, given the high amount of advanced technology all constantly being run at the same time while the suit is operational, it's entirely plausible that the suit is using more energy per second than the reactor is generating (i.e. JARVIS' comment that the Mark I chestpiece was not designed for *sustained* flight), resulting in a steady loss of total power available and causing him to switch to the backup power source while the reactor catches back up.
When Stark is lying on the table and asking Pepper to remove the power cell from his chest, the prosthetic chest used for the effect is moving up and down to simulate his breathing. If you watch Tony's upper chest you can clearly see that his actual breathing is out of sync with that of the prosthetic chest.
CNBC's two streaming tickers indicate the exchange stocks are traded on. The upper is NYSE, the lower is NASDAQ. Stark Industries has a three letter symbol, indicative of an NYSE listing but the quotes are displayed on both tickers amongst fictional companies named after Mad Money w/ Jim Cramer (2005) production staff.
When Pepper prepares to overload the reactor Tony instructs her to open all circuits and hit the master override. The circuit breakers are ratcheting style they cannot be placed in the open position by pumping the handle. To open the circuit the operator must press the trip button. Also on the close up the contact position indicator clearly shows the breaker in the closed position.
Pepper is a watching a recording of Mad Money w/ Jim Cramer (2005) on CNBC on Sunday, May 8th at 10:04 AM Pacific time. When she receives the "How big are your hands?" question from Tony, the remaining time on the recording jumps from 25 minutes to 15 minutes, while the clock stays at 10:04.
When Pepper is replacing the miniature arc reactor in Tony's chest, the prosthetic chest piece used to make a hole for the reactor to go in is clearly seen. The edge of the vest is a different shade of skin than his actual arm.
The goof items below may give away important plot points.
Stark secures his upgraded power supply in his chest by turning it clockwise (from our point of view) until it clicks into place. When Stane steals it, he also turns it clockwise to unlock and remove it, instead of counterclockwise.
At the end of the movie, Pepper Potts removes Tony Stark's handkerchief, fixes it, and replaces it in his breast pocket. When Stark appears for the press conference, he no longer has a handkerchief in his pocket.
Near the end when Stane removes the power cell from Stark's chest, his shirt keeps changing between having a hole cut out around the power cell to no hole and the power cell shining through the fabric.
Ironman encounters icing on his suit at his greatest altitude and assumes that the higher he flies the more likely Iron Monger will suffer from icing. Icing only occurs in visible moisture, cloud, fog or rain, of which there was none, plus it only occurs at temperatures of TAT +10 degrees C or below and above a static air temperature of -40 deg C. As Ironman was not in visible moisture and at the altitude that was quoted the air temp would be below -40, then there would have been no icing (and incidentally would be more likely to ice up on descent if he passed through clouds on his way down with the cold temperature of the suit).
In the end fight scene when Stane throws Tony and pulls off his helmet holding it in his hand, the eyes in the helmet remain lit until he crushes it even though the entire suit is powered by the arc reactor in Tony's chest. However, during his descent, Jarvis states the suit is running on reserve backup power. It is possible the helmet contains backup batteries, allowing it to operate when separated from the suit.