Temple of Kopec Boss Fight Issue

I was killed by the boss. But after he killed me, I managed to kill him at the same time through bleed and burn damage. I saw items drop when he died. I had no choice but to resurrect. But when I resurrected, it was at the first entry checkpoint of the temple. Had to run all the way back to the boss area. But when I was there, boss was already dead and all the dropped items gone. Boss should have not died with me and should have gotten immunity to damage right after I died. All that good loot gone because of it. I hope they can correct this.

PS: This happened in Cruel mode.