Okay, none of mine grenaded. But they most likely would have had I not change fluid early, and pulled the cover.If it was common place that differentials were grenading from such problems then I'd agree with you guys. But that is happening no more...
...most would have no idea what they'd be looking for when they're staring at the R&P.
For those that don't know what they're looking at...well, there's always the dealer, I suppose.
After all, a cracked ring gear tooth is somewhat similar to a cracked taillight lens, for example.
Besides, thanks to CF it would be easy enough to take a few photos and ask "Does this look normal to you guys?"
Worst case, there are entire books on the subject.