Treasure chest bug or working as intended?

Last night my ls went to raid the beastman stronghold. We manage to kill the boss and it dropped a gold key, oe of the member open it and it turn out to be senteniel pants but the problem was that it also loot into the chest opener inventory instead of loot list, and worse of all, the chest opener is a mage.

In addition, I heard the ifrit chest work the same way. What I wanht to now, is this a bug or working as intended? If it is working as intended... wth... SE perfect the chest system in the Darkhold chest, where there is a few minutes to decide who get the loot while it is in loot window.

I suggest making a bug report in the in-game bugs section.