Locking In A Champion Before Bans?

So we were in Champion Select in a Custom Draft Game and before we could ban anything our friend locked in a Champion. Seriously.

http://i.imgur.com/E6AWzMl.png

http://i.imgur.com/Gn9TwoJ.png

He was able to repick his Champion, but throughout the banning phase we could not ban Hecarim.

http://i.imgur.com/FMAYcBo.png