This was on local TV here and is a good example IMO for justified use of violence (by the fat kid). Aldrin's case is different because the stalker was not physical with him.
So what? There are many forms of non-physical abuse, that in some cases can be far worse than physical abuse. In this case, (years worth of) stalking, physical intimidation, verbal abuse, and continuing to harass and get in the Aldrin's face when he tried to walk away several times already.
This is why the law sided with Aldrin, this is why we have stalking laws (at least in Oz), and this is why non-physical abuse is widely recognised as a huge problem facing society. Aldrin did the right and
only thing remaining available to him to shut this guy up. It worked, and the law agreed.
Aldrin also had every right to think that things could have escalated after already having tried to walk away several times in this incident
Put yourself in Aldrins shoes and its very likely you would have ultimately done the same thing as he did. And if you didn't, well congratulations for you, a lifetime worth of future stalking and the same shit over and over. Have fun with that.