During opening sequence, the same bespectacled roller girl is seen waiting with her dog, then skating, then waiting some more in three subsequent shots.
K.I.T.T.'s speedometer's L.E.D. bar-graph display is incorrectly marked - the halfway mark is 100 m.p.h., but the three-quarter mark is 200 m.p.h. instead of 150 m.p.h., and the full mark is 300 m.p.h. instead of 200 m.p.h. Also, the bar-graph display is non-proportional compared to the digital (numerical) readout showing the car's speed - when the digital readout shows the car's speed as only 124 m.p.h., the bar-graph display is lit more than a quarter of the way across between 100 m.p.h. and 200 m.p.h.
When KITT gives the radio transmission to the pilot of the Lear 24 he refers to it as "634 Tango Delta" which would be N634TD, but the tail number of the plane is N664CL which would be "664 Charlie Lima".
After Michael catches Sonny, there's a scene of KITT parked in front of FLAG headquarters and you can clearly see that KITT has dual monitors (Season 1 & 2 dash) rather than a single monitor.
Just before KITT clips the wing tank of the plane, the dash is shown and it's clearly the Season 1 & 2 dash with the old voice-box and LED layout, rather than the revamped Season 3 dash.
When K.I.T.T. moves causing the barbell that 'Arnold' put upon his hood to drop, Arnold hops on one leg as if he was struck by the barbell, even though the barbell didn't hit him.
When Michael says to K.I.T.T. "Let's go undercover", all the windows black out, and red lighting comes on inside the car. Even though all the windows are now totally opaque and black, Michael is somehow able to see through the side windows to look in the wing mirror.
The ambulance at the airport is using a siren with a trademarked sound. In spite of this, there is no siren of this type on the ambulance, and it is also too large to mount under the hood.
As Michael is chasing Sonny ("Three blocks and closing") you can clearly see an antenna in his lap, most likely from a microphone or camera.
K.I.T.T. claims to have 1000 megabits of memory. 1000 megabits is 128 megabytes, which is very little. Certainly no where near enough to run an AI such as K.I.T.T., though in 1984 it probably seemed like a lot.
Mr. Renard refers to the poison as 'venom'. Venom is effective only if injected; the poison that is derived from the orchid is effective if either injected or ingested.