I know because I go out of my way to look at engines that have come apart in order to identify causes, and design weaknesses. I've taken broken shit to people who know more than i do and have them teach me how to look at the wreckage and make sense of it. Lee Schwartz (pro-stock, stock car, formula atlantic, other), Paul Julius (import machinist, works on Indy Light cars now), Morgan (Morgan and Sons machining, circle track, 10.5 outlaw, builds BRMS' engines and now pretty much everyone in Asheville's since Paul went to the Indy Light gig), and a number of others.
Nope, OEM bolts don't stretch, just like everybody figured out 12 years ago. HT noise says otherwise.