The correct answer is to raise both hands and eyebrows, excuse yourself from the table, walk off and keep walking until sufficient distance has been reached. Switching mode of transportation on the way is acceptable.
You'll often hear smart-alec martial arts masters say that the best self-defence technique is the 400m sprint, but they couldn't be more wrong. In truth it's the 1km parcour.
A colored flag means a sign giving a clue on something. It doesn't define a person, and can only be used to describe some abstract fact. You can say "getting angry when talking about the bear discourse" is a redflag, but saying "a man is a red flag" is not correct
Syntactically they should have used 'displays' not 'is' a green or red flag, but everyone divined the meaning of the damned sentence and the internet is garbage so who gives a rats