Maurice,
I just answered this same question on the ppbb forums - the bolt indeed broke.
Mileage was 115,000 mi. I'll have to ask what the computer had for over-revs.
I actually updated our IMS page again to include a more sure-fire way of identifying which IMS your engine has. I've had so many discrepancies in what an engine had versus what I thought it should have had, I can't guess which ones are single row bearing IMSs, hence the need to visually identify each one.
I also took some video of the failing IMS bearing as well as some photos of another dual row that was just sent in with 70,000 mi that completely came apart in the engine. It's posted on Youtube:
http://www.youtube.com/watch?v=xvLRMGs-Ti8
As you'll see in the video, it's physically possible to check for how much play there is in the bearing and gauge it's condition.