If you’re not security, killing someone because you think they’re an antag is valid hunting, which is against the rules. Additionally, unless you have authorization to execute someone as sec, you’re not allowed to permanently remove someone from the round (see round removal in the admin rulings page). The admin was following our guidelines on proper banning procedures. Trying to make some claim that “WELL ACTUALLY the ADMIN was the one who over-escalated!” just makes you look like an idiot.
This is denied. Sit out your ban and maybe read this so you know for next time: 7 Tips for writing a good ban appeal