I estimate renting over 1200 VCR tapes in my lifetime, and I've never had one unspool. The cassette problem was common enough that fixing it with a pencil was part of the zeitgeist, but I can't remember anything like that for VHS.

i had ONE cassette unwind. my less careful friend was always winding them with a pencil. the culprit? button mashing between fast-forward and play.