MiM wrote:What is it with you guys, thinking that beating a guy shitless is a smaller offence than wanking in a tree

To me, beating a guy shitless is not a smaller offense, generally speaking, without context, than wanking in a tree. If someone was in the woods, wanking in a bush, and someone beat the guy up, I would think the wanker rather innocent and the beater rather guilty.
Here, however, the additional facts left out of your statement change my analysis:
1. The wanker was a neighbor, known for curious sexual escapades, which appear to have included inviting underage local teens to participate.
2. The wanker trespassed on private property uninvited, and hid in the bushes outside of the window of a 12 year old girl's bedroom.
3. The wanker wanked while, apparently, peering in through said window.
4. The wanker was discovered, not in a wooded area wanking privately, but rather he was discovered by the child's father and/or brother on their property, just feet away from their daughter/sister, and wanking away.
Frankly -- if I caught someone outside my daughter's window and he started running, I would chase the motherfucker and if I caught him, I'd beat the living piss out of him until he stopped moving so that he could not further run or fight back. I would make sure he wound up in the hands of the police.