When Fiona jumps over fence, she is wearing wedged shoes, but when she is seen running through the garden she has different shoes on.
When Michael, Larry, and Jack jump off of the hotel balcony and into the pool, a close up shot shows that Jack broke his left foot. But his right foot is in a cast for the rest of the episode.
Removing a spark plug does not keep a car from starting. The car will start and run rough because one cylinder is not firing.