Xesht Crushing Fist Bug

Why do the Xesht Crushing Fist/Hand Portals (the move where the purple arms pop up out of the ground and slam down) not end when Xesht is killed? The duration of that move is like 5-10 seconds, but even if you kill Xesht in the first couple of seconds, you're left trying to dodge those purple slamming arms even though Xesht is dead... is this intentional?

If you manage to kill Xesht, but the purple slamming arms animation is still going on, you can die and lose all progress in the twisted domain even though you beat the boss and his death animation is occurring. Worse if it's T4 and you get one try at it...


Why am I able to be killed by a boss move when the boss is dead? Why is the boss death animation playing, indicating I've beaten the boss, when I still need to be "fighting" the boss and dodging his moves?