I've had the same experience but in a raid. I was on the step to kill the bosses on the Outbreak Prime quest and I just needed one more boss. I joined a group at Vosik and when I joined their party it was just one kid screaming at everyone. I thought that I would give them a chance, and we wiped 2-3 times before we got him. During those wipes though, he yelled at everyone and made it so difficult for the rest of us to communicate. I was planning on helping them beat the rest of the raid, but I just couldn't stand this kid, even after asking him to please tone it down just a bit. I just left without a word so I wouldn't say anything rude, and before I could leave the party I heard "omg what a rage quitter, he was a jerk anyway, etc". I didn't even say anything besides the usual callouts so needless to say I was pretty confused. Thankfully some nice guardians made my day by helping me get Outbreak Prime later that day.