Life Hacks/Wait for Billy's dad
Well, you didn't actually do anything wrong, so you shouldn't have anything to worry about. But then, going by the body language, it looks like Billy has his dad pretty riled up. It could easily go bad, you might very well have a confrontation on your hands.
Wait... didn't do anything wrong... confrontation with the police. Well... it seems there may be a pretty effective way out of this WITHOUT having to resort to violence. Just a simple camera phone recording and this guy may even turn into the latest example of an officer abusing his power and feeling the consequences. But then... testing out your new strength and martial arts skills seems appealing in a perverse sort of way. Or, you could just try diplomacy. You are sure with your skills you can clear up whatever kind of misunderstanding this is.
What do you do? Take out your smart phone Go the diplomacy route Anticipate a fight