Correct. You cannot switch to PvP default if you are in the middle of a RP fight. it has to be arranged beforehand. If you make an attack, you automatically have chosen RP default. If the other person returns with an attack in RP, that's RP default and no one can change that.
-Need to roleplay before the PVP. Just saying its not a issue on which default we use its an issue on a misconception that you can just switch to PVP default when you please.