You know, I heard that the original script of that scene had Indy getting into a swordfight, but at the last minute Harrison Ford hurt his wrist or ankle so they improvised. It turned out to be one of the more memorable scenes of the movie.
First of all, I can't believe this thread got ressurected.
Second, Harrison Ford was violently ill with flu-like symptoms and was barely able to stand for shooting anything that day so when he was cued to sword fight he drew his sidearm and ended the scene. Supposedly, Spielberg loved it and actually re-shot it with Ford carrying no wepon but a pistol and the bad guy going down, gut shot.
At least, that's the way I heard it.