any IRC op or channel op is responsible for their own bans and not others.
I believed that was the channel founder? or the one giving oper status? when I adding op's in my channels or give them oper status, then I let them know if they did something wrong, im a strong believer in give a reason for a ban/kick, not just kick a user without let him/her know why, same goes for the k-lines my opers set.