Well if everyone around him was acting angrily at him and he is presenting a YouTube short on a guy's rant, then you have to ask why multiple people are calling him out.
Because he is a troll.
EDIT:
I skimmed through his 2 hour original video, and for sure he was trolling them, in an anti-ICE protest, telling people this is not stolen land or whatever.
Even so a vast majority had a decent conversation with him and he just picked on a 2 minute segment when someone who had enough of his BS lashed out.
Hence a troll.