Freak coincidence or modded clients?

In lobby, first lobby for a few hours (No dodges etc) No one linked a stream or anything in lobby, (they usually do)

We had four champs hovered. Three of these were banned out by enemy team.

Sounds pretty normal if our team was picking god tier champs.

Our picks were Ashe, Heimer and Soraka.

How often are one of these banned, let alone all three?

It's highly unlikely that there is anything naughty going on, but what are the chances?