I just went to do T9 for the first time via FFXIV Duty Finder

So I just went to do T9 for the first time via FFXIV DF. I had checked out a video beforehand, but it was so much to remember that I knew it would have to be learned bit by bit as there was no way to remember every mechanic from every phase in one go. Also, keep in mind I'm an i118 DRG for this fight with i130 weapon.

Once in I had made it clear it was my first time and that I need to learn, though they probably knew since I watched cutscene, but just to re-iterate. Someone even said "Let's run it and see how it goes." I was expecting to forget something and die quick, but to my surprise I didn't. Everything went smoothly. I didn't die or even get hit except by anything you have no choice to get hit by like when we stack in the middle to absorb damage from that one attack. So then we get to the golem phase. I was not assigned to be a tank for any of the golems. I was told to kill green golem first, then blue, then red, which I already knew from video. So golems spawn, and since I'm not assigned to tank any I go to attack the green one with others, and no color swap had occurred yet during any of this. Green one is almost dead and all of a sudden a large golem comes up on us from behind, so I knew someone messed up or at least I think it was someone else and not me because I had never touched any other golem except green, and it was blue and red that merged into the super golem. So half the party is dead with only myself and a couple others from green last ones alive.

So here we are ready to go again. Everyone is just standing there not saying anything, then all of a sudden the duty ends and says I was dismissed. Needless to say I was angry considering how good I did for a first attempt and I didn't think I did anything wrong. My assumption was that because I was the only one that had mentioned being new that they just assumed I was the one that messed up without actually seeing who messed up. Afterwards I searched characters on Lodestone in hopes that one of them would be from Leviathan so I could contact them and find out why I was kicked, but it turned out about 5 or 6 of them were from the same FC on Behemoth FFXIV Gil server, which I won't name due to naming and shaming rule, while other 1 or 2 were from different FFXIV FCs and servers.