I've clipped wings with friendlies and had mine clipped when flying maneuvers in other games, before. I've also accidentally shot down friendlies due to bad visual ID and dropped bombs that took out friendlies flying low and close behind me. I wasn't kicked/banned for any of those instances and would have been peeved if I would have been.
It's your server, Eno, therefore your call, but remember accidents happen and five minutes can feel like an annoying eternity, especially when the infraction was truly accidental or not even your fault.
My $0.02 USD.
Shoot to Kill.
Play to Have Fun.