Look, I think the officers at a point exceeded their authority, but I sure don't want to discourage the police from checking on a 13yr old kid travelling with two much older men who obviously aren't relatives. Also think there's more to this than the parents are letting on. What sort of dance competition is this and what the hell, in this day and age letting your 13yr old go overnight anywhere with only older male teachers - that's just dumb. Open the freakin' newspaper if you need a clue as to why. The parents homeschool.
None of these things smells too badly alone, but together there's a whiff of something not so savory going on.
As a side note, anyone who wears their hat to the side like that deserves a customary beatdown to begin with.