I am certain there are many of us with the same train of thought.  #1 I am not a brow beater of our law enforcement. It is just strange as  to the 2 different rules of "reasonably" believing his life or the the public is in danger. You or I try and use the exact same template of fearing for our life. That's it. end game. Life of living in a concrete zoo for a handful of decades. In recent times(past 25 years especially) leo defense will say he was driving right at me. He was wrestling for my gun. He was going for an unseen weapon. My long gun rack had loaded weapons, locked of coarse.  
To sum it up; if your vehicle is stolen with a firearm(s) inside. You are instructed to file a report online. A cruiser stolen. Shoot because that's DIFFERENT.  Mrs Smith is correct to hypothesize. Over paid with a life. 
I hope that the officers pride did not escalate this incident just because he lost control of the situation but we'll never know because the the system is gamed in support of Leo's