With the man watching television, the amount of beer in his mug frequently changes, often being fuller in subsequent shots.
When Dr. Hartwood is outside the warehouse where Chris, Sunshine, and Prince are hiding, he tells the the police sergeant not to shoot because Chris has his arms around Sunshine's neck. Chris actually has his arms around Prince's neck.
During the filming, Jay North had braces put on his bottom row of teeth. There are scenes where his close ups show him, pre-braces with his front teeth crooked. Other times it is clear in closeups that he is wearing braces.