bro is immortal
if anything he's going to get sick and it won't have anything to do with her but she will think it did so he comes to visit
and if this doesn't happen it should have
That only helps if you already think that she actually considers it a kiss and not two people falling onto each other (which, you know, is kinda what it was)
He can't help it. He's Japanese. It seems like they have to apologize for everything to anyone who isn't a kouhai. Also, it appears that it is a social faux pas to accept a compliment.