A3S, I was on solo healing duty until the split. Got comfortable enough with the fight to know i could just keep regen and medica 2 up and throw one or two heals here and there before the boss starts its bitchslap routine, so the rest of the time is spent in cleric stance.
At some point someone takes more damage, I drop cleric stance and heal them up. From that moment, my stance dance was completely messed up and ended up realising too late that I was trying to solo heal the AoE bitchslap in cleric stance, leading to a dead MT and, soon after, a wipe.
Nobody was paying attention to me, so the MT was blamed for not using a CD in time

In my defence, after coming to terms with my embarrassment, I did say it was not the tank's fault, but he was still held responsible cause his CD wasn't up in time.