I'm with Curt on this one.... These are the same recepts I use in my work (P&S BR15W).. The pitting on the neutral wire is a giveaway of a loose terminal.. I can torque the %@%$ out of those without stripping the terminals out (Unlike Leviton, which I usually snap the head of the terminals or strip em out, By HAND!)
Possible, but unlikely... Was a shared neutral being fed through here with both hots on the same phase?
