Revealing mistake: In the fight between Julie and Ned, when she does the last kick to take him down, it's obvious that she doesn't actually kick him.
Revealing mistake: One of the monks bowls a gutterball which jumps out at the last second to become a strike, but as it does the 10 pin begins falling before the ball contacts any of the pins.
Factual error: When Eric goes to help the guy who got hurt after bungee jumping at the dance, the guy's line is long enough to allow him to lay flat on the ground. If it was really that long he would have crashed into the floor and not gone back up.
Continuity mistake: When Eric arrives at the docks and gets out of his car and approaches Ned, watch Eric's car in the background. There's nobody else in view at this point, but you can see that something is being splashed onto the car. In a shot a couple of seconds later, Colonel Dugan and some of the other Alpha Elite boys come from out of hiding from nearby and one boy starts splashing gas onto the car.
Continuity mistake: When Eric pulls up to the docks to fight Charlie he is wearing a vest, as he gets out of his car the vest is still seen, a brief moment later the vest has disappeared.
Revealing mistake: When the monk bowls the gutterball, you can see a lever pop out in the gutter and guide the ball back onto the alley.