I don’t think it’s gameplay sabotage. I think it’s just a wiener thing to do.
Obviously he’s incredibly childish and insecure. Feels he needs to take his personal issues out on random people in a video game.
It’s sad really.
I personally avoid inviting the Latin and Brazilian servers because I’ve had some bad experiences with then. Far more than good. But I’ve also met some really good players who ended up being the best in the group.
And yeah, I’ve noticed from my personal experience that they make more mistakes than American servers. But that’s no reason to yell and belittle them.
People make mistakes. By the time you’re done yelling and chastising someone you could have killed the extra mob and moved on with the run.
Report the dude and move on with life.