I will be interested to see how this turns out. The guy was brandishing a deadly weapon. He showed an odd combination of irrational, aggressive, and suicidal behavior, and he was insisting on going back into the store from which he just got busted for shoplifting. Wouldn't a reasonable person conclude that he is likely to do something bad in there? I wonder what IS considered to be the proper protocol for dealing with a situation like this one.
If he got back inside and stabbed someone, I suspect the story would be how two police officers were on the scene and did nothing to stop the tragedy.
Although the officers couldn't have known this, the guy previously served time for attempted murder. He sounds like a dangerous nut.