Continuity mistake: When Tommy is escaping into the mountains to try and help, a small bit of his jacket tears off onto a tree branch. MacGyver later sees it, but the branch that the torn piece is on looks entirely different. (00:21:10 - 00:22:10)
Witness for the Execution - S2-E15
Continuity mistake: When David and Maddie are debating whether or not to help Lawrence Everett, the towel David uses to wipe shaving cream off his face jumps around during the scene. It's around his neck, then in his hands, then on his shoulder, and back in his hands, etc. (00:15:40)