Other mistake: In the scene after Mini-Me's and Austin's fight when Austin is sitting on the space toilet to "eject" Mini-Me he picks up a copy of the London Times, as seen on the cover page of the newspaper. On the last page of the newspaper there is a weather page showing a map of the United States. Why would the London Times have the weather for the United States instead of Great Britain?
Other mistake: In the scene when Austin is rising out of the pool in the beginning, the water that shoots out of the platform he is standing on is actually going into the water shooter/sprinkler instead of coming out. This is due to reversing the film (so he comes out dry), but hey, it still looks weird.