So, what I see here is a guy, who purposely singles out a player in his live stream for poor DPS, rages and mocks him in front of his audience, while displaying his in-game name, leaving the fellow open for more harrassment for other players.

I'd say the suspension was deserved. I have nothing against parses, and most people are cool about them, but when people act like this, they ruin it for the rest of us.

As for the inconsistent banning and not using outside evidence, it's far, far easier to alter a random screenshot you took than it is to alter a legitimate, verified live stream on a platform like Twitch with the streamer actually speaking. So I can understand them using this as evidence vs a regular screenshot.