Be mindful that in these positions your sense of what criticism is thoughtful or not becomes dulled. It is a defensive mechanism to deal with generally unfair behavior directed at you and perceptions held of you.
Differences of opinion are to be expected between individuals. Many take it too far by assuming a difference of opinion is equivalent to another's incompetence in making decisions or a flaw in their character. Its very easy to boil any issue down into a one dimensional right or wrong scenario, especially when it is forgotten to use empathy and try to figure out why people might view something differently to you.
Even when people mess up, it would do everyone well to remember that we all make mistakes. We should all strive to have the conscientiousness necessary to never let our responses to them become unwarranted personal attacks. Everybody here is a person and deserves respect. Its hard to make a mistake as a TF2 volunteer that is any worse than innocent in the grand scheme of things. Expressing disagreement does not require vitriol, and including it is likely to make those you wish to educate just react defensively and become more set in their ways.
I know that's something I struggled with.
I should note that isn't necessarily a response to Reero's post and more of a general observation. I don't know the context behind that screenshot, but I don't think its important in terms of what I said.