Exactly, in a wing over turn pulling pretty high 'G"s one is actually using his ELEVATOR to do the turn. If he's lost elevator authority, his turn would be wide of where it's supposed to be, and if his control cables are loose (like what could have happened if he lost his trim tab), there's no telling what other surfaces they might affect if they wrapped around other cables or rigging...(rudder most likely) loosing all but aileron control would make it VERY hard to control the aircraft..and at those speeds and that altitude, just no time for anyone to recover or even bail out..