I feel so bad

Did my weekly Jaina Mount run yesterday. We had a protection paladin doing it for the first time. Leader told everyone to not interrupt and made sure the tank knew what he was doing and specifically made him remove his interrupt from his bar.We pull, everything goes fine until someone kicks Jaina. Turns out it was the prot pala using Avengers Shield. Everyone in the group flames the tank, calling him all kinds of words and he gets instakicked. He apologizes straight away several times in /say for being new to the game and ruining the pull. I immediately felt so bad for him and whispered him to not feel bad about it and just to know that Avengers Shield interrupts.I know it’s annoying for the rest of the group someone wipes us but I WISH some players could be just a tiny bit more patient and not as toxic in certain situations. Poor guy must have felt like a criminal.