Mission Impossible 2 - Wrong Director in Credits
If you look carefully during the rock-climbing sequence as the names of the cast and crew are being faded in, you can clearly see the words: "Directed By John Woo". This was a major slip-up - perhaps the most major of slip-ups possible. John Woo was not the right choice of director for this film. In fact, he was utterly appalling. He cannot even speak proper English, which poses a curious question for a man directing actors: how can he understand the intricate and subtle nuances of the performance through the words they are saying if he is not the least bit familiar with the way in which the English language is used by westerners. His action direction was the usual "everything must be symmetrical" fashion. The second biggest slip-up was the composer. Hans Zimmer wrote a terrible score for a terrible film, which doesn't justify his efforts in the least.