Putting aside whether Veitch is/isn't an ar5ehole, it's not actually illegal to photograph/video people in a public space without their consent. The wider point is we have people out there (e.g. the guy in the video) who require mental health care and either aren't receiving it or if they are, it's inconsistent and patchy.
And again referring to the guy in the video, with absolutely no disrespect to him, I reckon I'd feel more than slightly uncomfortable to be in the vicinity of him. Of course no right-minded person would condone violence against people in these situations.