Also, you have someone who is in emergency mode that is disconnected from your emergency response and acting on instinct. Restraining him and letting him cool off is not an insane move just to expedite and clear the way for a more organized response. Are there other ways of doing that? Yes, but lets be honest, thank god he didn't get shot.

(Not a commentary on police in this case, though I have my own feelings on the matter of police brutality. But it would have been so easy for the police responding, entering with no information, to see him running around with a gun in hand, assume he was the bad guy, and just shoot.)