I saw that yesterday. Scary! I'm guessing probably some poor welding or like you mentioned, some inferior parts without enough strength.
When I read it yesterday, the guy had still not responded to any of the questions. I did a little searching and I think he bought it like it was. Goes to show there is some scary stuff getting built by inexperienced and unqualified people who don't search out the "right way". And then being bought by unknowing newcomers.
I've always shyed away from cars with a lot of work done by inexperienced and unknowlegable people. Did an interior quite a few years ago that was built using 1/2 inch drive (for wratchet/socket use) u-joints for the steering column joints! I wonder if Craftsman would warranty those?
You've got to check something out good if you buy from someone you don't know.
One more reason for a NSRA inspection.
I'll quit now.....