When to kill/loot groupmates?

[DrKvothe]

Yesterday I was in a full group with a shaman whose actions greatly annoyed me. He would canni down to <10%, risking low hp aggro, and he would run around for minutes at a time, clearly missing lots of med ticks. It wasn't entirely clear what he was doing to help us kill the mobs. He would regularly try to melee (while at low hp and claiming OOM), and every so often would talk about how stoned he was. I sorely wanted him to die.

It would have been so easy. One nuke and done. One dot and watch him panic. I don't think anyone else in the group would have minded. He could only have been bound far away or right next to me, so I probably could have gotten another kill in before he LNS'd.

I didn't do it, and it's been eating me up inside. I dont understand "red etiquette" yet. When/how do you kill idiots you're grouped with? Do you break group first? This rage is threatening to make me explode please help.