Honestly, it is a question of good taste and courtesy. 99% of the time people stay within acceptable bounds in their roleplaying. For the very small minority who do not, the best policy is generally to just ignore them. They already look extremely petty in most cases. No need to lower yourself to their level. In the event that the RP has some political effect, then you may need to counter with your side of the story, while respecting the rule that Tom just linked: Game mechanics always trump RP. If a lord is kicked out of his lordship via a peasant revolt resulting from game mechanics, then that is exactly what happened. You may choose to RP varying reasons as to why it happened, but you cannot RP that it did not happen.
