Those so called Law Enforcement Officers LET HER DOWN! They now have to live with that. They should have protected her. Makes me sick.
What should they have done? Have you seen the body cam footage of their entire interaction? The women called 911, police pulled them over, separated and questioned them both. Minor tussle and arguing was the impetus for the 911 call. They asked her if she feels safe, she did. She didn't want to proceed with further action against her boyfriend, and wanted the both of them to be on their way. The police doubly, triply made sure that was her wishes.
What sort of extra-authority do you think they have? They cannot kidnap her, arrest her, have any grounds to arrest him. Even if they did, either would be released immediately for having not committed any serious crime. After release, they would've likely reunited, as they were far from home and traveling together.
The police don't know what the boyfriend would do in the future, and are under no expectation to have that crystal ball. They can only act on circumstances in front of them. That interaction was minor. There is nothing further the police could have done that was within their purview or lawful authority.