A dog inside a home is lawfully contained.
A fear that one will be attacked is a fear, not an example of rationality. You are attempting to justify a government employee’s irrational behavior.
Why are you attempting to justify a government employee’s irrational behavior?
Did the police officer break the law? Will he be arrested for shooting the dog?
If her “contained “ dog had bitten a friend the friend could sue her. Her insurance company would have to pay up.
The one with the real irrational behavior is the woman who invites a violent boyfriend into her home, putting her mother and children in danger and then wants others to take care of her business ie the taxpayer.