I mean, he did tell them she was the one who did it, so why the fuck did they believe her when she just told them "nah, not me, it was him, honest..."? Takes special kind of stupid to be that much of an idiot.
So, when I getting attacked by a guy with a dagger, probably a mugging or so.. if I tell him to throw away his dagger, he'd just submit and throw it away... Good to know, it may just save my life.