Continuity mistake: At the beginning, Phil says to Tracey on the phone regarding the wedding, "That ain't gonna happen." In the end when we loop back to that scene, Stu tackles him before he can say that line.
Continuity mistake: In the scene where Alan says Doug is clear to move into the right lane, right after the truck starts to swerve, the camera switches to showing Phil and Stu. There is no truck in the frame, but when it shows Alan and Doug, you see the end of the truck passing them.
Continuity mistake: When their apartment room is messed up you can see some wine bottles all lined up just like bowling pins. In the next shot when Stu gets up from the floor it shows the main door of their apartment room and the wine bottles are no longer there.
Continuity mistake: In the scene in the police station when the two cops have the taser class in front of the kids, Alan gets tased in the neck and fall on top of the table in front of the classroom and his arms arms are facing upward toward his head. Moments after that, there is a shot from the back of the classroom and Alan's arms are in a normal position by his side.
Continuity mistake: After Mr. Chow runs away, you can see that the crowbar is in a different place from where it was when he dropped it.
Answer: In the pictures, it is Stu that is fighting with Wayne Newton. It could be assumed that Phil got involved afterwards, but it is never shown.