I thought (arrogant me) that I had made every mistake in the book - and had mostly learnt from them. Well, this morning I invented a new way to ruin a roll of film. I was winding a roll of 120 FP4+ onto a Patterson spiral - went well, I usually struggle to get 120 film started, and I reached the end of the film. Felt for the scissors and cut the join between the film and backing paper. Some idiot, who shall remain nameless, also cut through the fabric of the changing bag at the same time. I did actually develop the film (Rodinol 1+ 50) but it was mostly black.
I also had a roll of Rollei Retro 400 to develop so I got my spare changing bag out and loaded that onto a spiral. When I reached the end of the film, I decided to be a fast learner and did not use the scissors. I tore the film from the backing paper - first four frames useless with static flashes.