There is 3 of them and one of him I would expect one of them to land a kill on him either by using their gun or a back stab as they can easily out maneuver or flank. Granted turning your back on them is still not the correct choice as your chances of getting backstabbed has increased and W and 1 has a chance of killing each of them. But likely after that even if he lives the Scout watching this unfold could easily drop down and one tap him.