Simultaneous Kills Delete Boss Loot

I was doing Secrets in the Dark and I died to his 'big attack' and then I killed the boss about a second afterwards.

This as a side note actually spawned the quest item at the previous 'rust pillar'. I found it pretty much by happenstance when I was wandering after.

But more importantly, I am assuming the boss dropped something good that I might want to pick up, but because I had to respawn I couldn't get it.

This just sucks.

I don't ever want to be in a situation where I killed the boss from a chaos damage tick or something, and then just have to deal with the fact that because I also died, I get nothing.