Yeah, all you said is right. But for auto targeting specifically, I've found a number of times that if I'm moving right before/as the mob dies, I won't auto target anything at all within my cone. No hard tests to back it up, but that's been my experience. I put two and two together when seeing other characters strafe around a mob, but as you said, you can still auto attack, shield block, and WS, all things that you wouldn't be able to do if you didn't see it. Maybe it's more a bug specifically with auto targeting while moving, or maybe we're in a sort of rapid state of in view/can't see.