Deliberate mistake: Several of the matches Nacho loses, he should actually have won. In Mexican pro wrestling, it is illegal to rip another's mask off, and results in immediate disqualification. This happens twice to Nacho, both in the fight with the midgets and in the final against Ramses.
Deliberate mistake: When Zoom is moving the documents from the desk to the floor for Marsha to pick up, she quite blatantly catches him two or three times, but continues on with her business.
Deliberate mistake: The Benchwarmers originally had only three players, and then only one who could actually hit. Despite this, none of the (supposedly competent) little league coaches chose to simply walk all the players and force an out.
Deliberate mistake: At the end, there is no way that the RV managed to roll over and flatten the vehicles in its path.