I will play the devil's advocate for a bit. Before I continue, I would like to say that I don't support any kinds of toxicity online (be it in a game, a forum or whatever), nor OP's desire to be kicked, because the latter is rightfully a bannable offense. And I also think the person should have left the group from the very start and accepted the deserter debuff instead of wasting so much time, seeing that the premade group was slow.
However, I don't really agree with some people, that the premade tank shouldn't have gotten a punishment for the caused delay. For me, it classifies as Disrupting Gameplay. Here are the rules quoted by Thorbjorn:
And I would like to bold the "only to idle" part. So, let me get this straight. It's a bannable offense, if a player afk-s for a couple of minutes before they rejoin their group and not inform others about it at start - if a dps does it, it mainly affects them - but a premade group idling "10 minutes" and delaying the run w/o informing the randoms what was going on is not considered to be "disrupting the gameplay"? In this regard I can understand OP's frustration and I honestly think he was right to complain. He should have added a full video of the entire rdf run to support his thesis. Yes, w/o it we can't really trust the truthfulness of his words, maybe he exaggerated some facts, in order to look more like a victim. Regardless, I wanted to point out the contradiction in the comments.
And regarding the kick at the end - I can't believe that the GM was so direct in his response and ppl are defending him. I truly believe, that the GM should have taken a more diplomatic approach and not add more fuel to the fire. Greedman45 doubts, that OP is a good player, and thinks this was the real reason for the kick (+ the toxicity). This might be true, that's why the GM should have gone with a different response. The most obvious is, that the evidence is not clear enough and in the shown video OP doesn't look that innocent as he claims. The GM could have stated, that there are no general rules regarding the kick mechanic, but OP's toxic behaviour was a valid reason to get him kicked.
Personally, I think a rule concerning the kick mechanic should be made. There a lot of forum posts where people complained to have been kicked from a premade group before the last boss, which made them saved for that instance for nothing and forced them to waste even more time in the rdf queue and in the next dungeon. And if the system put them in a saved dungeon again (due to the bug), this would have caused a greater disastrous experience. But, all of this is just my humble opinion.
@ Greedman45 - Maybe OP is not showing on the dps meter, because he could have selected the "show damage from the last fight" option or idunno.