IMO, crazy and/or stupid is not a good defense. If they assault someone outside of an institution designed to house these folks, they'll take their lumps with the sane and not-stupid assailants.
If the crazy/stupid person can not manage to interact with folks without getting violent or becoming a target of violence, perhaps they don;t need to be roaming free in the wild.
As for this incident:
1. Chasing, tasering, OC-spraying, and thumping on anyone for a bicycle ticket? Really, in what world is that appropriate? Chief Wiggums needs a time out of his own.
2. Dude ran back to his house. Let me repeat, he ran back home. Mail him the ticket. No need to treat him like a King in the foyer.
3. Also, how overstaffed is the PD when 20 cops show up to give one 17YO feeb a bicycle ticket? Would they have to call out the state's National Guard in the event of a shoplifiting?