I'm wondering if it's just me or do others experience biased drops when farming?

For example, let's say the final mission to kill Harg. I am on my own and I've almost killed him, then another player enters the room. 9 times out of 10, the player who joined late will get the relic. In some cases the other player doesn't even need to raise their sword and still walks away with the loot. This happens in all missions, not just Harg. It seems the more effort you put in to killing the bosses, the less chance you have of a drop.

Anyone else noticed this?