I'm not defending Aliens for their faults, but I will defend them for what is not their fault. This sort of cam failure is due to the cam umbrella-ing. It means it was undercammed. It either was placed undercammed, walked undercammed, or the rock crushed out, resulting in undercamming. In the Fishers, I'd bet on the latter of those. The laws of physics are pretty simple and dictate that, since no two objects can be at the same place at the same time, unless the cam is undercammed, it can not invert. It is true that certain cam types WILL hold an umbrella placement... if the rock does. That includes double axle designs like BD camalots, and in some cases (with lower then original strength), cams with positive milled camstops- like the newer metolious FCU's and HB's.