We discuss each case individually which is why it's different each time. Taking your example in the Heap, often those threads spiral out of control very quickly and when we realise it's degraded into personal attacks we would have to infract four, five, ten people. In those cases we prefer to do a mod post as a slap on the wrist to everyone involved, and only start handing out infractions if people ignore us and have to try to get the last word in. Same deal with warnings, we give them out when we give the poster the benefit of the doubt but also let them know their behaviour isn't okay and they need to do something about it. Again, if they ignore us, they get an infraction.
Other times it's clear to us that the post broke the rules and the poster should have known better, so we will give an infraction with no warning.
So I'm afraid we can't really give you a 'standard' infraction process. But we don't act on a whim, usually at least 3 or 4 mods chip in with their views on what we should do before someone actually warns/infracts/mod posts. This is why you should also remember that although one particular mod may give you a warning/infraction, it doesn't mean they're the only one who had a problem with your post or that they decided what to do about it. Usually it's just whoever first reads the thread after enough mods have agreed on what to do.
I hope that clears things up for you guys.
Just one last point - please don't discuss the details of your previous warnings/infractions here. These are private and not meant to be shared with the board. If you have a question about a specific case please PM one of the mods, or Michael if you think it's appropriate to take to him.