Other mistake: When Brian takes a picture of his friend Doug on the boat, the picture shows Doug in a different position than that of when the picture was taken. (01:21:30)
Continuity mistake: During the first conversation Tom has with his uncle at the bar, the level of the beer rises and falls several times. (00:05:00)
Continuity mistake: In one of the scenes where Tom is throwing the bottles around, he throws up a spirit bottle, grabs it behind his back, and then it is a wine bottle.
Other mistake: When Brian & Doug are singing and walking drunk though the city, they come to a subway which Doug falls down. When Doug lands from the fall there is some water next to him but in the next scene the water has vanished.
Continuity mistake: At the start of the movie, the guys are in an LTD chasing a Greyhound bus so Tom Cruise can get on. They pull ahead of the bus and pull over to stop. The bus stops really close to them almost hitting the LTD. In the next scene they get out of the car and have to walk about 20 feet back to the bus. (00:01:35)
Continuity mistake: Elizabeth's character, Jordan, meets Brian on one day. Then the very next day (looks to be around noon or so) she comes to thank him for helping out yesterday. That evening, she and Brian go with Doug and Kerry to a club where she answers Kerry's question of "How long have you known him?" by saying "About 10 hours."