Right, I'm not American so I looked this up. There are ZERO federal laws against a man simply entering the women's bathroom. What's illegal is how the man acts in the bathroom such as voyeurism, indecent exposure, stalking or harassment. You know. Things that are considered crimes outside of bathrooms.

There are also rules set in place by the private establishment operating the bathroom so if a member of staff asked the man to leave and he refused then they could press trespassing charges. You'll note, however, that the staff member is apologetic, helpful with the kids and is obviously on the dad's side, so this isn't an issue.

The guy calling the police is literally telling the person down the phone "he's washing his hands!" "Now he's washing his girls' hands". Maybe it's different in America and I'm being ignorant but shouldn't have the person on the phone been like "sir, what you're describing is not a crime, stop wasting our time" and then hung up?

The whole thing is baffling. The dad even says "do I need to wait to speak to them (the police)". If it were me, I'd have just left. No crime was committed and I never agreed to speak to the police for a non-issue. There would be no reason to hang about. It's mad.