Her being armed didn't intimidate him; the sound of sirens as she spoke further didn't scare him off. Some people took the A Man's Home is His Castle far, far too seriously.

...And then she discovered the other reason he wouldn't stand for any loss of face even enough to humor her before dismissing: he had friends over. Drinking buddies, clearly. Heavy drinking buddies. Oh, lovely.

She didn't want to hurt the boy's father in front of him, but she was rapidly having no choice... and it was getting rapidly more complicated. And then Luke was brave or foolish enough to try to talk to her again and got shoved, and a knife went into Mr. Moreau's offending wrist.