Being stricter with ingame griefing doesn't need to be a ban, admins can mute players who do this whilst still allowing them to play. Like any punishment, this can be used to discourage that behaviour without being stupidly heavy-handed like a ban would be.
valid point. i make sure to warn people not to abuse polls, for example.
the evidence is not always clear, however, as you point out yourself. sometimes, a reason for a poll may be stated in the dead's chat while i am alive. i have no way to find out without asking and relying on what others tell me. that sucks because friends of the offender have an incentive to lie. further, i'm still playing at the same time so there may not be time to ask because it would mean letting my team down. finding a reasonable balance between being a player and an admin is a challenge every admin must face.
sometimes i have very limited information and using my intuition is my only option in decision making. while intuition can be great at speeding up complex problem solving tasks with the exact same outcome as a gruesome lengthy analysis, it can--at least in a few cases--also lead to a decision that's terribly wrong. in unclear situations, many admins stick to the benefit of the doubt rationale, but obviously, that can be just as wrong.
that's where admins must reflect upon their mistakes. at times, an excuse is in order, and in any case, we must make sure not to repeat our mistakes. players on the other hand must realize that being admin is a learning process as well and give us a chance. if both admins and players refrain from being anal about everything that happens to them, we have a solid foundation for everyone to have fun without making anyone worse off.