The point is, if every one of those deaths were someone who presented a credible threat and were actually trying to kill an officer, why do so little of them succeed? If anything, they have the element of surprise on their side. Police are often only given little ammunition and training time every year, literally just a couple boxes of ammunition. Anyone just casually going to a gun range every couple of months for fun is going to have more experience than most law enforcement officers.

If they were only killing every criminal that actually attempted to kill them and had the means to, there's no chance the defenders in that situation are coming out successful 20 to 1.