Why should the other person get to decide and be judge on what's rude and disrespectful? If I believe it's rude if you do not kiss the ground I walk on and that's it's disrespectful if you don't obey my commands, tough shit for me and anyone else who thinks that way.
If someone is rude to you in your eyes and based on your standards, how you react is still on you and is your responsibility. You can still be respectful to rude to people.
Respect is a two way street, agreed. The other person decides if it's rude to THEM. You decide for yourself if something is rude. The knight will decide for himself if it is rude to not call him Sir. I think it's wrong for someone to say it's NOT rude to NOT call him Sir. It should be up to THEM.
If someone is rude to you in your eyes and based on your standards, how you react is still on you and is your responsibility. You can still be respectful to rude to people.
Respect is a two way street.