Anyone who has the DVD and has watched the commentary already knows a lot of these slip-ups, like this one, but here's for the VHS owners:

In the part right before Ed Norton's character "destroys something beautiful", when they're all the waiters and they almost just castrated the old guy, they run out those doors into some parking garage of some sort. As they are running through the doors, you can notice Meatloaf's character in the background, and his pants have fallen down! It's quite funny, because if you look closely enough, you can see the fat pads and stuff on his legs.