Cigarettes and Alcohol and Rollerblading - S2-E8
Revealing mistake: When Ted jumps onto his bed (when the nun replaced their mattresses with bricks), you can see both beds are bouncy when Ted lands on his bed and Dougal lifts back the covers on the bed half way through the episode. (00:19:20)
Answer: Ted was using his real hands to control Father Jack's wheelchair using a remote control - the fake arms were so no-one would see him cheating.
Sierra1