Continuity mistake: At Joey's party, when Alex and Michael are talking about Seth's girlfriend, the food on Alex's plate keeps changing places in between shots. (00:10:00)
Suggested correction: The plate is just turned around... The food does not changes.
Continuity mistake: When Joey and Howard are clearing up after the party, we see that Joey throws all the rubbish he has in his hands in the bin, yet when the shot changes he has more to throw in the bin. (00:20:30)
Continuity mistake: When Michael is talking about Seth's girlfriend, Joey has a board of cheese and grapes out. When the shot changes, the grapes have disappeared off the board. (00:05:35)
Continuity mistake: Just after the opening credits, when Joey runs out to see Jake, Jake has one hand out in one shot and then puts the basketball in both hands. When the shot changes, his hand is out again and then he puts the basketball in both hands again. (00:04:15)
Revealing mistake: When Joey is climbing the wall, you can see that the piece of wall he breaks has a break line in it.