LOOT REROLL MECHANICS: Receiving the Permanent Champion for One of the Shards Input

So. I Put SKT T1 Kalista, Bilgewater Katarina (I hate the hat), and Fiddle Me Timbers in the Champion Skin Shard Reroll machine hoping the RPG Gods would love me and grace me with something [slayer-pantheon-thumbs] .

However, I actually received SKT T1 Kalista, one of the very skins I didn't want in the first place. Now I know that was extremely unlikely to happen, but it seems like that shouldn't be a possible roll to begin with :/

Thoughts?