The flailing punches don't accomplish a great deal, though he'll probably feel a few of them in the morning; it's the reckless and frankly stupid neglect for his own safety that gets Charlie the upper hand, and if it doesn't quite knock Harry off, it costs him the advantage and leaves him open to more direct hits.

Which, thanks but no thanks - as soon as he's vulnerable he takes one more swing for diversion, then takes the initiative to try to put space between them. Because by some (massive) miracle, he hasn't forgotten about Chloe, and his interest in... well, showing off, let's be honest - it still outweighs the urge to beat this asshole to a bloody pulp.

So instead of laying into Charlie again and trying to keep him on the ground, he makes a valiant effort at shifting to the side and getting to his feet. Probably dumb, but hey, the guy's got a split nose; hopefully it's a distraction.