Barry didn't know what he wanted to do, he came all this way, so full of anger and hurt, and he had no idea what to do. In the end, all of those emotions came out in a punch. Yep, Barry sunk that slow, he lashed out. And he hated himself but he hit Leonard as hard as he could and... yep, that really hurt his fist. He didn't back down though, he just glared at Leonard. "You're a horrible person. Where do you get off acting like this?"