Continuity mistake: In Jimmy King's match with Diamond Dallas Page in the beginning of the movie, DDP tosses Jimmy out of the ring through a table. From the ceiling shot of Jimmy going over the top rope, we can see that there is nothing on the table, but when Jimmy goes through the table, there's a bunch of papers and coffee cups on there as if someone was sitting there.
Continuity mistake: Near the end, during the triple cage battle between DDP and King, right before King grabs the belt he powerslams DDP through the top tier of the cage. As DDP is falling, there is one shot where he is almost completely vertical, seeming that if he continued on this he would drop squarely on his neck and/or top of the shoulders. But not 2 seconds later he hits the mat and he is completely horizontal, showing that he was most likely dropped from about 1 foot above the camera.
Continuity mistake: When Gordy and Sean are sitting down eating burgers Gordy has some food on his face - in the next camera shot it has gone.
Other mistake: During the scene where Shawn and Gordy are in the van with the nuns, watch Shawn's hands closely, he's not actually playing in time with the sound of the guitar.
Continuity mistake: During the four-post massacre, when they show lead up shots, a couple of the guys are obviously going to land short. But in the final shot, it shows them jumping out a little further.