Didn't he stop at the start line?
I was trying to figure out what your friend did, and why he would wind all the film to the end. When you put a roll in, you line up the start arrow or line or whatever you film says, with an arrow on the insert. Then you close the door and wind it a few winds before it should stop. If it doesn't stop shortly, something is wrong. I would think generally about two winds of the lever should do the trick, and if it doesn't you should know something is wrong.
The only thing I can think of, and I did this stupid mistake myself once, was to run the film directly from one roll to the other without going in front of the pressure plate. As if it was 35mm film. I caught it right away. (I'm not supposed to do that sort of thing for another 20 years.) Could that have been what he did? Ric.