Random champion selected

I was in champion select today and I had selected Tristana. When I clicked "Lock In" it said, "Are you sure you want to lock in? You do not have a champion selected, and a random champion will be selected for you." or something like that. Thinking it was a bug, I clicked yes. It then randomly selected Evelynn for me, which did not fit with my team comp at all. Is this happening to anyone else?

---1 800 Try Hard

EDIT: We won the game with a Sion support, Evelynn top, and Jayce mid. Who knew.