Years ago, when I was trained as a moderator by an ISP with a large online community, I was taught that, it's ok for people to criticise the contents of a post, however it is not OK to criticise the poster as that's what invariably starts a flame war, everyone is entitled to their opinion or interpretation of whatever is being discussed, even if they are completely wrong!
In a nutshell it's better to discuss rather than argue, it also helps to just double check a post before submitting it, just to make sure it comes across as you intended and isn't misinterpreted, would you put it like quite like that if you were standing in front of the person? Occasionally, what is intended as a humorous comment comes across as a criticism, seen that a few times on here.
If it's any consolation, this forum is incredibly well behaved compared to some of the message boards I had to deal with, trying to get the combatants to ignore each other was nigh on impossible, especially when you had groups of people joining in taking sides or complaining about the ongoing dispute or reporting every single post / poster they didn't like.
The Jointed Rail Goodies thread was several years old.
