Continuity mistake: When Fink is explaining the difficulty of the boot on the chalk board, he draws one circle on the toe of the drawing, it then changes to two after he throws Bo Bo and says "Sorry" and changes back to one circle again. You can tell that they are two different drawings altogether.
Continuity mistake: The beer that the guys make from the stolen recipe is a reddish-brown color. When the Wolfhouse brothers begin to bottle and sell the beer, the beer is in light green bottles. The beer inside the bottle is not reddish-brown, or else the bottles would have looked darker when full. The unopened bottles look like there's a light-colored beer inside of them.
Revealing mistake: When the American and German teams are playing a drinking game involving putting coins into glasses while downing pints, the camera switches to an angel at the end of the table. If you look at the front two people's hands, they are going past the pint glasses, and the coins are disappearing, yet the pints are still filling up with coins.
Visible crew/equipment: When everyone gets together in the beer training place and the guy says "Lets drink some beer" watch his face and you will see the shadow of something that looks like a camera. (Don't get it confused with one of the guys arms or mugs, if you look where the shadows come from you will see).
Other mistake: Near the end of the film when they have the 5 boot drink off, at times the boots is at such an angle that normally beer would spill out, if any was actually in it. Plus every time they put down the boot the areas around their mouths are dry, which should have been soaking wet.
Continuity mistake: In the scene towards the end of the movie where the Americans are preparing to face the Germans in the all boot double or nothing challenge, when they are shot from the side there are 10 boots on the table. In the next shot when we see the American team face on, only the Americans' 5 boots are still on the table. Then when they go back to the side view in the next shot all 10 boots are back on the table.
Revealing mistake: During the fight between Cherry and Landfill, you can see several times that it is not Cherry, but a stunt double. The stunt double is much thinner and has much lighter skin. It is best seen when she is on the ground and Landfill is kicking her in the stomach.