You're being a bit silly at this point. A few weeks ago I noticed there was a gash in the Incipio Feather case holding my HTC M8.
http://i.imgur.com/FJeEyuR.jpg
I have ABSOLUTELY NO idea how this happened. I don't recall my phone ever hitting something that hard to cause this gash. But am I blaming Incipio, HTC, T-Mobile, etc at this point? Of course not. Logic tells me that something happened where my phone got bumped and it didn't seem like a big deal at the time, but obviously made more of an impact than I thought. My best guess is that it happened when I had to hit the breaks a little harder than usual and it slid under my seat. I don't have anything damaging under the seat that I know could have caused that, nor did I slam on the breaks so hard it would've flown hard at something. But, that's what I'm going with.
Like has already been mentioned, had there been an actual problem with the metal, you would have heard many people by now who have been only as rough as being slightly aggressive in putting cases on who have scratched their metal bezel. Where are those claims?