Maybe they did it because they noticed how badly affected some of the scenes were because of the bad cropping that was made in this part of the film and not for the dirt, the PAL transfer basically show the same amount of picture information to the right of the frame as the NTSC frames I posted when taking the overscan of a CRT-TV into consideration. But they also recropped the rest of the film which doesn't make any sense if that was the main reason, maybe to get rid of the "light-artifact" seen throughout the film.