playing an unowend skin in new draft

After banning and picking all champs, I switched champ to play ahri. I never looked at skin selection as I thought it would go to one of mine. When I got to the game load screen, it said I was playing firefox ahri, I dont own that skin. I was able to play the full game with the skin though, no problem there. After the game I checked and made sure I dont own it, and I still dont. Also, after the game, the person I switched champs with said he does own firefox.