It's hard to see and hear in this video and hard to make judgments IMO. When confronted with someone with a weapon officers want to live through the encounter to get home to their families. Part of me, my heart hurts that a mentally ill man was killed when the dog may have been able to stop the threat. Part of me understands when officers are confronted with someone with a weapon the game changes and they want to get through the encounter with no injury or loss of life to officers.
Several years ago locally, there was an officer killed during a traffic stop. When the guy was found in the woods, he was told to drop his weapon and didn't. (Admittedly this is a different situation in that he was already a known deadly threat to LEO) Deputies shot him a total of 68 times. When the media jumped on why he shot so many times the sheriff's answer was simply - 'that's all the bullets we had or we'd have shot him more. Quite frankly we weren't taking any chances"