The players(collectively) have an enrage timer.

[Arabian_Wolf]

I think people have forgotten that everyone must first understand mechanics and have high DPS output to burn a boss and ignore the incoming mechanics. They've begun to just skip straight to burning, even on first-time runs.

But there is no need to swear and scream as if the player did kill someone dear to them,

Regardless of that today we did the same boss (2nd boss in Fractal) and this friend did interact with those glass tube to summon the add.