During the banning phase of a ranked game, the enemy team was able to ban 4 champs and we were only able to ban 2. What would have caused this?
Currently there is no mode that lets a team ban more than 3 champions.
The screenshot you provided does not make any sense, since even if there were 4 bans per team, the left team should have 3 bans, seeing as how bans alternate between the two teams. It is most likely a client-side bug.