[q=edczxcvbnm]If you slip up and post something you shouldn't have then you are screwed. Sorry I clicked on the wrong file but I am only human. I am not perfect and I don't pretend to be perfect. Instituting such a rule would mean that you obviously are arrogant enough to believe you are perfect. No one is perfect and they should pay a price.[/q]I disagree. Bannings for accidental slip-ups can be justified on numerous grounds:

Bans aren't just about punishment, they're about prevention. If someone's negligent enough to "accidentally" attach the wrong file or link to the wrong image, then banning that person's account removes a threat of the same thing happening again. If a poster takes a reasonable amount of care, such errors should not occur. Banning people who do slip up in that way prevents a recurrence. Of course, minor infractions don't warrant an outright ban, and they don't receive it either.

Also, honesty is a crucial factor. Who decides whether a violation was deliberate or accidental? Anyone can attach an inappropriate image than say, "OMG! I thought the filename was 'my new car' when it's actually 'yaoi with cucumbers'. Sorry, my mistake, won't happen again." Similarly, someone who flames could go ahead and plead innocence - "I didn't mean to say that the Admins prefer goats, honest! Just a typo."
A "trial by jury" format, like you suggest, also has shortcomings. The 'popularity contest' principle can apply too easily, with members rallying to support a 'fan favourite'. A legendary figure like HOORJ or HOOTERS would be unlikely to receive equal treatment compared to a new or unknown member.

Allowing the defence of 'honest mistake' would create new avenues for abuse, with devious and dishonest members "inadvertently" committing serious breaches and getting away with it. There are few reliable ways to assess the honesty of someone's mistake; in the interests of protecting the forum, outright bans are the only way to go for members showing a blatant disregard for the forum's rules.