Well, that’s not a particularly thick Newfoundland accent, but it’s certainly a Newfoundland accent.
Irish. Notice when he says ‘Look, I’m just trying to help’. Note the way he says ‘help’. It’s subtle, but definitely there to me. Maybe, as another poster said, it’s someone who was born in Ireland but came to the US (or Canada) when he was a kid. I’d guess Canada, as some of the other stuff he says has a subtle Canadian ring to it.
Not that it’s all that important…there are assholes in every country, and we certainly have our share. And I’ve noticed that they tend to be concentrated in first person shooter audio forums especially. 
-XT
He’s an Irishman trying to sound American, and failing. It sounds really obvious to me.