Steve, "clearly, he has something in his left hand" - what that is exactly, is the question. It looks like the behavior of someone running with a walkie talkie. But again, clearly, he has something in his left hand.
It looks more to me that he is almost certainly covering his ear with his left hand, to muffle in anticipation, the sound of more shots coming, perhaps.
It's more likely that he has something in his right hand, or sticking out of his right pocket, probably his Radio. See Below.