Co-op Corruption Vaal Altar in Story (Legacy of the Vaal Quest)

It seems, if someone is using the corrupting altar to corrupt a equipment piece, and someone else, put their item inside of the altar aswell at the same time, whoever uses the altar keeps their item, but the other persons item disappears, seemingly stuck in the altar's inventory instead of dropping on the floor or putting it back in their inventory.

Addendum:

We have discovered that after it being stuck in the vaal altar's stash, it did corrupt my friends item aswell, and kept it in the stash, during a temple run we discovered the item was inside one of the exalted workbenches, he got his boots back and found the altar Did infact work on them aswell, it just did not drop his boots and he had to find it in a bench/stash of some kind.