When I make rules about game-mechanicy stuff (like the one that spread everybody's points out, or whether or not we have chocolate in the world, or the tyrannical building policy) I am open about it, chat with people, often ask them to make their opinions and preferences known (unless, like with the building policy, I have no intention of heeding those preferences) and heed said preferences within what I think is reason, and explain my reasoning when I announce the decision. These things become 'rules' which are documented. Weirdly, as all-above-board as that is, some folks /still/ thought I made that sheet-nerfing ruling to benefit a pal.
When it's player-conduct stuff, there are only a couple 'rules' and while it's more detailed than "don't be a dick," what's written makes it clear that you don't have to violate a written rule to get removed from the game. This kind of thing ends up a private discussion. Of course somebody's gonna think it's unfair a lot of the time, that being the somebody who got the talking-to and his friends to whom he misrepresented the conversation. But I have no idea how to minimize that effect without making a situation where fucking up not only means you get a boring conversation with me, possibly a temp ban, etc, AND get embarrassed before the entire game.