I have noticed both HRE and Greys do it. Didn't get any screens, so the only thing you have is my word. I usually write in chat that they should stop it. Usually met with silence...
Oh for gods sake, don't compare us with GO. Even if it would be only 1 person in HRE doing so (I doubt it), they are fucking up the balance with their whole freakin clan being on one team on the first round. And if they don't switch the team they go spec for the first round and block the server for other players, which happened a lot lately.
As long as you don't prove your statements, just stop posting stupid accusations like that. The only one who got banned for that was Pue, and that was many many months ago, right after it got officially bannable. After that noone of HRE got banned for this...we actually have fun fighting each other on the first round.