During the shootout in the hospital where Virgil kills bad guy #1, the camera is switched to show bad guy #2 driving off in the blue Firebird. When the scene switches back to to the interior of the hospital, the blue Firebird can be clearly seen in the parking lot outside the window.
When Tibbs is wading towards the supposedly dead Wallace Posey in the water, you can see the vapor from Wallace's breathing.
When Tibbs is telling the Chief that he heard his saying before, over Tibb's right shoulder you can see the reflection of a spectator watching the scene being filmed.
Although the show is supposed to be situated in Sparta, Mississippi, the true filming location is revealed when the Chief picks up Rattler and takes him for a ride in his car. When they are driving away you can clearly see the sign for the Hammond, Louisiana Fire Department's Station No.2 in the background. Hammond, Louisiana served as the filming location for the series' first season.