When I sent mail out my mail, I included the technical expert who sent the mail that MLH told me about (but didn't forward, another reason on the long list of why he sucks).
Expert responded with a snarky "If you'd read my mail you would see that we shouldn't be setting this to that, and that we should be setting this in the startup script."
I responded with an equally snarky, but cheerful "Well, if you'd sent me your mail, I would have read it. 8-)" (The smiley at the end makes it cheerful, you know.)
He responded by bouncing me a copy and apologizing. We then engaged in some witty and cheerful banter.
That it someone who doesn't suck. He quickly and good-naturedly apologizes for a mistake, and doesn't demand that I read his mind, and doesn't explain how it was my fault he didn't include me. This is why even if he can be a pedantic blowhard who adds hours to meetings with pointless nitpicking, he's still a great guy that I enjoy working with.