But as I wrote in the FAQ, I fired off that email in under an hour in reply to a fast-moving thread on an email list where people knew me by reputation and wouldn't question my skills; the totality of my "research" was trying to reproduce the original numbers from memory ("500 miles" stuck in my head, but the distances to the places I remembered pinging did not); and I didn't ask anyone else to edit it for me.
All of that would have been ridiculously unprofessional of me as a writer for something intended for as wide an audience as it went to. But I had no idea it would be forwarded so much and so often (nor so many years later, now decades after the original event!).
And that's why I really prefer it when people link to the canonical version I maintain at http://www.ibiblio.org/harris/500milemail.html with a link to the FAQ.
It's also a reason why short business emails are better than longer ones. You can always go more in depth. It takes skilled restraint to touch on only the most relevant details without losing the larger point.
A critical rule, however, is to omit detail, (a reader is unlikely to question an explanation they make up themselves) and most importantly, to omit details you know to be wrong. (It is impossible to nitpick a statement that is never said)
He knew this was largely wrong, and didn't really improve the story, yet he said it anyway. It should have been summarized in a single sentence, leaving out all the problematic assertions that the slashdot trolls leaped on.