Well you're right on the money. I don't actually think it was my fault. Its generally considered a stay needs a right battering to actually break, and it tends to be learners with no finesse who generally break a stay by grossly over-pulling then failing to check. I was/we were ringing up and as my bell approached fully raised and I was expecting to stand, the rope was snatched out of my hand and disappeared up to the ceiling then it jumped the wheel.
General opinion seems to be it was probably already 90% or fully broken when I started the raise which rhymes with my own opinion, but as a visiting ringer it sounds dreadfully naff to claim that! So I sucked it up and made/fitted a new one for which they all seemed surprisingly grateful. An interesting process I was pleased to perform anyway.