My impression from watching the video was that the two officers were at opposite ends of the proficiency spectrum. One planted himself, took solid aim, and fired. I suspect he made the mortal hits.
His partner appears to blaze away as he clears the area, in what looks to me to be panic. It's not hard to conclude HIS shots did most of the injury to bystanders.
Powder smoke- The Smell of FREEDOM!
I don't shoot to kill; I shoot to live.