Kovics' Cadillac limo changes into an unmarked police car, complete with flashing blue light on the dash, when it jumps the drawbridge.
When Tubbs' wire malfunctions in Kovics' limo it starts playing music is a impossibility. Police wires are one way only. Mostly for cost but also for this reason.
There are several instances of voice overs for the lieutenant that do not match the actor's own voice.
At the 12 minute mark when Tubbs is at the station complaining about not getting a raise, he is clearly wearing earrings in both ears, after a cut away shot he reappears not wearing any earrings.
Just after Crockett calls for Tubbs to give him some covering fire in the climactic shootout, Tubbs fires seven shots (sound-wise) from a revolver, in the time-span of only five muzzle-flashes and from a revolver which should hold only 5 or 6 rounds.
Camera operator's shadow visible during the credit sequence after the train goes by.