[The Canuck]

We have to consider a whole slew of things.

First off, the continuum of force. When the guy came up off the hood, the cop was justified to use pepper spray to control the threat. Whent hat failed to work and he was getting the snot beat out of him THEN he was justified in using the firearm.

Next up, I find it interesting that the cop would just shoot him once and expect him to stop.
The axiom I was taught in the Army was, "You stop (shooting) when he stops (being a threat)". So he should have continued firing until the big guy was laid low.

Next up, all it takes to jam any pistol is to place it out of battery or in the case of revolvers, jam the cylinder. Considering what was going on, it would not surprise me if the pistol jammed when it went out of battery because the big guy grabbed the pistol and pushed the slide back a bit in his attempt to grab it. If any of us, with whatever choice of type were in that same situation, we would have had to same problem, revolver or autoloader.