Fuel exhaustion? For the dual-engine failure, I was actually talking about a failure of an engine that is accompanied by an associated transmission problem (uncontained blade failure, shrapnel, etc) - misspeak on my part, should have said combined engine/transmission failure. In that case, the both the core engine and the transmission are damaged, preventing power transfer from the opposite engine. Auto-rotates are n/a due to the lack of inertia in the rotors, and what kind of glide do you really think there is with those wings?
Regardless, the majority of my post was devoted to the fact that the guys who are supposed to be supported by this aircraft - the ones I spoke to at length in theater - don't like it. It does not matter what potential the aircraft has if the operators can't infil/exfil as they need to or if they have to leave their equipment at home. In the CV-22 case, it is solving problems that the supported units don't need solved.