As one of the people who loves being that guy in another community: They're not only very good at digging up and pointing out precedents, they likely have systematic archives of everything that remotely relates to the decisions they wish to see made.
I feel like sometimes users with negative Karma like crazy become even more obvious to mods. Sidenote: I still yearn to see what HN looks like to mods and what not. Not to cheat the system but to understand the system more (I love knowing these sorts of hidden details).