It pains me to see him unwrapping paper-backed rolls of film in room light, then using a strobe to document the appearance of the the roll (before developing). The fogging you see at the top and bottom edges of some rolls is from light leaking around the edges of loosely-rolled spools; it happens even with modern 120 roll film. There's a good chance he's fogging some of the rolls due to his handling.
I was actually watching him do that and I was thinking the same thing. I don't know anything about developing but I was thinking that if the casing has even a tiny crack then the camera flash would ruin at least one photo.
The nice thing to do would be to send him a friendly email and tell him about it. Maybe he just doesn't realize it.
