Regardless of what happened between the mother and the cop, the police are not allowed to interpret the law. They are enforcers of the law. If no law was being broken by the child, he had no reason to take her into his custody in the first place (regardless of his own opinion), and should have consulted with his captain and the DA (“I witnessed such and such, is there a crime being committed?”) and leave it entirely up to the DA whether or not to approach the mother.
I went to Texas A&M as a grad student in the 1980′s. I got an apartment off campus as the roomie to a near-washout undergrad junior. He is now a physician of some renown in Louisiana, which just goes to show you that people change with age.
He has the distinction of being perhaps the only Aggie ever to canoe across campus, and perhaps the only Aggie to ever snow ski across campus, both due to freaky weather during his time there. I’m pretty sure he is the only person on earth who has done both.
One person’s lack of common sense is another’s bragging rights.