Epic win

At a wild guess, whoever kicked that ball didn't mean to hit someone on the head and would have regretted hitting them on the head. To my mind, that's clear evidence of a fail.

You're thinking too literally Oliver. 'Wins' and 'Fails' can occur regardless of their intent. In fact the opposite of someone intended action could end up being a win or a fail. In this case, a ball kicked (regardless of intent) has hit a person flush on the back of the head. That's very unlikely and can thus be viewed as a 'win'.

I was once playing rugby with a few friends. We were messing around down the park and kicking it around to each other about 40 metres apart. At one point, person A kicked badly and person B started laughing and running towards person A. At the same time, Person C kicked a ball in that general direction and managed to hit person B directly in the back of his head. It is probably one of the funniest and most unlikely things I've ever seen in the flesh.