Option to help avoiding baning your teamates prepick

I normal drafts, I have seen a few times people baning a champion that was prepicked by his teamates, and they did not even mean to, they just did not realise, because to forgot to check, or even worst, the champions has been prepicked late.

So, my idea is to have some kind of warn when you select a champions to ban that has been prepicked by an ally (before clicking ban), and / or a confirm option saying something like "PlayerName in your team has prepicked that champion, are you sure you want to ban him?"

I know people should just watch out, etc, but, that would just be helpful for both those who dont care AND mistakes from the others.