Hi Jen, a welcome from Shropshire from one of the old 1960's crag rats, who probably too much of his youth in Snowdonia.
Tumbles on the end of a rope have now been replaced by such, as so aptly described by yourself. A particular one was after successfully descending a little known waterfall in mid-Wales on the end of a whippy sapling. A successful action that was marred by slipping on a rock trying to cross the stream below. My rucksack saved me, much as yours did, though it did not stop my Nikon bridge camera from a total immersion. The rest of my X Wales walk went unrecorded, but the happy outcome was the 3yr old Nikon was just in the insurance that I thought I had been oversold by the camera salesman, and I got a brand new Canon as it was the nearest replacement they could offer.