The baseline assumption is that you follow the rules of the game. As you stated, in order to play a mythic game you have to add house rules. We never did that.Because people are different?
There are many different images of a monk in many cultures and subcultures.
If the DM doesn't set the baseline assumption, any headaches they get from genre confusion is their own fault and falling back on Authority at that point erodes it.
But it still goes back to the basic question. This happens in a game. It's not a mythic style campaign. How should it be handled? What option is there except for the DM to say "no", possibly with follow up questions and suggestions?