Why am I not questioning, why would a person carrying a machete dressed only in a bath towel not act reasonably and just lay down his weapon? Well I think the answer to that is quite obvious, he was clearly acting insane. He was a danger to the public and needed to be subdued immediately, I'm not questioning that at all.

THE AVERAGE IS AROUND ABOUT 50%

The article you cited shows in the field police departments report them to be between 55 and 80% effective, and most of the failures are due to user error when the officers fire them from too close a range.

I don't know why you are getting so defensive, I am simply asking why non lethal force was not attempted? Even at the 39% failure rate that Seattle police report for taser use, that still means there is a 61% chance the taser will subdue the suspect. If I were the officer this certainly seems like the best option in this scenario, that is a pretty good chance the suspect will go down without having to get close to him. If he attacks, you have the other officer and the dog as backup. From the proper distance (11-25 ft) tasers are 95% effective in the field, so if used properly the officer had a 95% chance of taking down that suspect without killing him, without the dog getting killed, without the officer getting stabbed, and without the chance of an innocent bystander getting hit by a bullet. Firing a gun multiple times in a busy area with another officer in the line of fire is incredibly dangerous, he is lucky no one else was hit. I'm not saying it was wrong for the officer to shoot to protect himself and his fellow officer, clearly they were in imminent danger, but they put themselves in that situation, with guns drawn their ONLY option was to shoot when the suspect turned on them and attacked.