Continuity mistake: Even after KITT's voice modulator changes to the three bars in the episode "Hearts of Stone," any shot of KITT starting himself up still shows the old voice modulator (a simple red square).
Continuity mistake: Steele props up the deceased Kalil and puts a cigarette in the dead man's hand. When the camera angle reverses, the cigarette moves to a different position: first it's between fingers two and three, then it's between three and four. (00:25:45)
Testimony of Evil (Dead Men Don't Laugh) - S1-E6
Continuity mistake: At the start, the glass on the left is poisoned. The guy picks up the glass on the right, but still ends up dying.