Tabula Rasa - S1-E3
Revealing mistake: With Marshal Mars in pursuit, as Ray drives his pickup, he holds the steering wheel with his left hand, and his stiff prosthetic right arm is down at his side. When Kate grabs for the steering wheel, in the side exterior shot the stunt driver is quite noticeable, as he grips and turns the steering wheel with his good right hand/arm. (00:30:40)
Revealing mistake: Season 5, episode 8, "My Name is Mac Taylor": When the killer sets himself on fire, he's not wearing any gloves. In the next shot he is, to protect the stuntman from the flames.
The Night of the Living Duelists - S3-E18
Revealing mistake: When the Duel Ghouls are approaching the main characters, in the shot where Chazz walks to the front of the crowd, there are three ghouls who are drawn black, with no facial features or clothing, to give off the impression that they are shadowed. (00:16:00)