Sounds like the cops did everything calmly, cooly, and correctly. As to the original tenant who retrieved his apparently unloaded gun: WHAT WERE YOU THINKING? If the gun is unloaded, you would have been better served grabbing a hammer.
Maybe I'm jumping to conclusions. The tenant may have planned on loading the revolver and events unfolded too quickly. Still, I'd rather grab a loaded gun than an unloaded one.