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.
Revealing mistake: Right before Jaden and Chazz start the duel, in the shot of Crowler saying "Indeed, and in front of the whole school too", there are two Slifer Red students who appear to be standing completely still and motionless. (00:09:43)