Rolling 3 Skins into Skin Perm: unlocking skin SHARD after

So just now, I rerolled 3 random skin shards into Jurassic Cho Goth. To my curiosity, I saw I had a normal skin shard for Jurassic Cho. I decided to 'upgrade into skin permanent' which, normally the text is grayed out and unable to click. It allowed the upgrade and simply sent a skin permanent in the inventory. It then allowed me to attempt an upgrade to unlock the skin, but simply came up as error. This was on my main account, not PBE. I don't want anything back I just wanted to see what happened, and maybe bring it up as a potential bug, as it can mess someone up possibly in the future. Cheers.

TLDR: Reroll 3 skin shards into skin permanent, use ALREADY OWNED skin shard of same type and upgrade it to permanent, receive skin permanent and simply lose essence.