Kill Zalmarth, quest completes, die to creeps before getting loot

I wouldn't be writing this if it wasn't soooooo unsatisfying!!!

I tried this boss fight, no guides/spoilers/builds or anything, with my weak build. maybe did the fight 50 times, i know insert get good comment here.

I finally get the kill on the boss, but his remaining spinny dudes do the freeze and ping you to death combo. revive. the zalmarth dude just bonks his head on the ground, drops his green quest item and falls down. no boss loot. sadge

any mechanic that allows you to die while loots live on the screen needs to be removed. i think this sort of thing has happened to me in early iterations of dark souls where you kill the boss but dont get his drop or the large amount of souls cause you die randomly, but the boss/quest is registered complete so you can't do it again without another playthrough. super punishing.

the boss death should trigger the minion deaths. or quest completion/loot drop shouldn't trigger until boss and minions are all dead.

i know there's like a possibility people while try to exploit kill themselves to get the loot drop multiple times, but i think a basic trigger like that wouldn't be exploitable.