While racing against Rooster, Michael Knight's clothes change from a green/white outfit to his regular black leather jacket for one shot.
When Jamie drives off the road to avoid the incoming cars, she has a pile of boxes with her which are clearly visible. A moment later, just before her jeep starts tumbling down the hill, the boxes have disappeared.
When Joey is trying to turn off the alarm clock, in the closeup shots the time shown is about 3:09, but in the long shots, it's about 6:35.
When KITT Turbo Boosts over Rooster, the front end of the car gets damaged upon landing. In the next scene, KITT is fully repaired again.
When Michael crouches down to pick Joey's door, a part of the strike plate is clearly visible in the door frame, revealing that the door isn't even closed properly, let alone locked.
When Rooster tries to open KITT's bonnet with a crowbar, KITT's voice-box has the NORMAL CRUISE light illuminated, even though he has no driver and the engine isn't even running.
When Michael races Rooster in the final scene and takes off from the starting line, the footage is clearly accelerated - it's most evident by observing the pace at which the pedestrians and other traffic suddenly speed up in their movement.
In the final scene, Rooster challenges Michael to a race. As Michael goes to the street via the driveway, he accelerates firmly which causes KITT's nose to scrape against the road. As this occurs, flakes of metal fall off KITT's bumper and onto the street. KITT is meant to have a Molecular Bonded Shell which is impervious to all types of damage.
When KITT hits the high voltage wire, the view of the sparking/arcing circuit boards is actually the insides of an RCA XL-100 color television set.
Mr. Roskovitch tries to cut into K.I.T.T. with a cordless grinder which has a wood cutting blade mounted upon it. A wood cutting blade is not designed to cut metal.
When K.I.T.T. is hacking the alarm clock, a picture of a computer circuit board is shown - one that was used to represent K.I.T.T.'s own circuitry among other uses.
As Michael is racing towards Road's End, KITT tells him that in exactly 10.3 seconds, the lead cars will reach Road's End and be incinerated by the bomb. KITT and Michael then talk for a few seconds as they race towards Road's End, then KITT says "10 seconds and counting". This is impossible, since a few seconds earlier, it was exactly 10.3 seconds.
When KITT Turbo Boosts over Rooster, you can clearly see a roll-cage through KITT's rear window.
Michael swaps Joey's briefcase full of cash with an empty briefcase containing nothing but a "Jack in the box" toy. The weight difference between the two cases would've been immediately apparent to Joey as soon as he picked it up, however he acts totally surprised to see that the money is missing despite carrying the case from his room all the way to the meeting with Mr C.