League Champion Select bug

So, my brother is tilted off the face of the earth right now.

He was being ADC. During champion select, he had Sivir selected. Then when it came time to lock in, the game immediately switched his pick to Kassadin for him and he was unable to dodge the que.

I don't know what's causing this bug, but this needs to be fixed. He lost his promos because of this crap. Fix it NAO.