Able to use skins that I don't own in dynamic queue

Not really a bad thing, but still a bug nonetheless. When I swap champions with someone else, I sometimes gain the ability to use skins I don't own. In a recent game, I swapped Corki for Lissandra with a teammate. I was able to use the blade queen lissandra skin, even though I don't own it. Not really sure how exactly it is reproduced.