Continuity mistake: In the wide angle shot of Chief Gillespie approaching Virgil Tibbs at the train station, there is a dog on the platform, in between Gillepsie and Tibbs. In the next shot, a closer view of Gillespie approaching Tibbs, the dog is gone.
Other mistake: When the convoy of getaway vehicles arrive at the scrap yard, after dropping the loot of at the airfield, two of the jeep type vehicles have the same registration number - 247EJF.