It's perfectly sensible for commoners to have opinions about how authorities should behave. The opinions may be wrong, just as the authorities may be acting poorly. But nobody should be above questioning or criticism, particularly those with with power. My view, as a mere commoner, is that anyone worth shooting is worth shooting as much as required to get the job done. Anyone threatening with deadly force, be it a knife or otherwise, is fair game for shooting assuming the shooter has a reason to be there and is not responsible for escalating the situation in the first place. In this case, assuming the reporting is correct, everything looks fine. The only issue is whether the reporting is correct. We obviously can't trust police (which is too bad, but simply the reality). So, people have questions and should expect more than just the word of the police. This is why body cams make so much sense these days. If I were a cop I would very much want one.