Losing quest rewards when dying at the same time as the boss.

I just defeated the boss in the Tomb of the Consort. With their final attack, I died and due to the Damage over Time I'd applied, they still died.

I saw the quest rewards and drop and when I resurrected, the boss was still dead but I got no rewards at all and can't seem to fight the boss again.

Is this a bug or an intention change?

same thing happened to me, Im pretty sure that its a bug. some ppl even lose quest items too reportedly.