When Banner's tire goes flat the wheel has a hubcap. When he gets out and looks at it, the hubcap is off. When he goes to change the tire the hubcap has reappeared.
Right after the Hulk begins to change back to David Banner for the first time (by the side of the lake), Banner looks into the lake and mutters "my God" when he sees his reflection with white eyes. He swats at the water, and when the image clears up he sees his face with his normal eyes. Look at the frame right before he swats the water; his eyes are already back to normal.
As the Hulk is smashing Banner's car (right after the very first transformation), the headlights of the car switch from on to off and back to on.
After he received the massive dose of radiation, as David was driving home he had a flat by running over something in the road. the first look at the tire and wheel there is no hubcap, then after getting the jack and spare and jacking the car, there is a hubcap. also, when the Hulk starts beating the car, windshield and door glass do not break like that, they broke like plate glass and not safety or auto glass.
Right after the Hulk begins to change back to David Banner for the first time (by the side of the lake), Banner has both his jacket and shirt back on, even although they were ripped when he changed into the hulk.
The plaster cast brought to the lab by McGee was not what would have been the result of casting a footprint, instead it looked like the Hulk had stepped in a tray of plaster. the print was a depression.
The laboratory explosion was caused from the reaction of two agents accidentally mixed in the chemical storage room. Chemicals with such explosive potential would never be stored in hazardous proximity to one another.
When Banner catches Magee hiding in the laboratory closet, he says, "How would you like to find yourself arrested?" Magee responds, "Good idea, call the cops, I'm dying to hear you explain that." (He is referring to the extensive damage done to the chamber.
No crime was committed, and therefore Banner and Elaina are under no obligation to explain to either Magee or the police the damage caused to the chamber. Elaina explained it to Magee as a pressurization test that exploded. If they had to explain, this is a totally reasonable as well as believable, considering their nature of work.
When the Hulk spots his reflection in the lake and runs his hand through it, the make-up on his hand washes off.
The Hulk, in destroying David Banner's car, flings his fist through the windshield; it breaks into large shards, revealing it to be breakaway glass that actor Lou Ferrigno could smash without serious injury to himself. Automotive glass is required, by law, to be safety glass, and whenever it is actually broken, it would form a "spider-web" pattern. This is a revealing mistake that Kenneth Johnson himself pointed out in his commentary on the home DVD release.
Obvious "lady" stunt double for little girl, when she is in water on long shots.
Dr. Marks (Susan Sullivan) Tells David, "I always liked your mother" and David replies, "She always liked you". But in Homecoming (1979) it's clear that David Banner's mother died when he was a small boy, but he didn't meet Dr. Marks until Medical school, so his mother and Dr. Marks could never have met.
When Elaina's colleague mentions a reporter from the National Register has been snooping for a story, and when Jack McGee introduces himself to David, the mouth movement does not match 'National Register' in both instances. This also implies a different name was originally going to be used.
The gamma-ray machine David uses is for use on people; there would be no logical reason for the tech to recalibrate it to a potentially lethal 2,000,000 unit maximum setting.
Taking into great account that they wanted to simply keep the story moving along, this can be forgiven, but it's still worth contributing. Banner's cover story to the police officer concerning his car holds absolutely no water, and he'd be subject to a great many more questions. His cover is that his car was missing in the morning and that he thought a friend who has a key to it had taken it. Then the police would start an investigation into "the friend" and further complicate things. So essentially, Banner feigning ignorance would not be accepted whatsoever.