Apparently he called the police himself, Hamilton police having, supposedly, participating in a program where citizens can call them for mental health support.
So they went there knowing what the situation was apparently; not sure how it got to the point where there were about a dozen of them there, but if I asked the police for "help" and in a short time found myself surrounded by a bevy of armed police, it would violate every single concept I have of living in a free society. Some people in such situations will habitually react in certain ways, even if it's contrary to their "normal" character. Even the nicest person has a breaking point when they fear for their lives.