My gut tells me that this is just a case of bad luck - ultimately strap lugs aren't new technology, and a lot of cameras use/have used them, so they're not new technology - they're proven, and should be more-or-less failproof... or at least the incidence of failure should be pretty low.
My money's on failed retaining washer, or bad peening job failed to keep the retaining washer on.
If we haven't seen a rash of these failures, I'd reckon it's a single bad peen, and not a systemic manufacturing failure.
At least I hope that's the case