Rebecca Chernoff asked: How would you deal with a user who produced a steady stream of valuable answers, but tends to generate a large number of arguments/flags from comments?
dmckee answered: @RebeccaChernoff Hardest possible scenario, huh? If they contribute to the comment noise, then cleaning up after them can be a warning. If that fails, a private email after consulting with other mods. The sin bin for a short time if they persist, but I'm thinking of Rich B. levels of persistent conflict generation.
Sklivvz answered: @RebeccaChernoff First of all, I would be present on the site and nuke flame wars from orbit. This is not where you come to fight. Aside, I would approach the user in chat first (using the new @@ tool, possibly) and try to reason. I would explain that the community is more important than any single user, etc.
Sklivvz continued: @RebeccaChernoff If that fails, and the behaviour continues, then I would use a formal warning, and then repeated suspensions. The main point here is that one user can spoil everybody's fun. Even if they are high rep... Actually, especially if the are high rep, they should set the golden standard.
David Zaslavsky answered: @RebeccaChernoff First reaction: just reply to the comments asking everyone involved to keep a level head and avoid saying rude things. I might delete comments if they seem excessively bad and/or irrelevant to the question. If that fails after a few instances, then send an official warning (moderator message), then after that, suspensions of increasing length, starting with a day or two, until it's no longer a problem.
David Zaslavsky continued: @RebeccaChernoff (continued) Contributing good answers can earn a user some leniency in the "disciplinary" process, but it's not an excuse to be rude and get away with it.