They were not the ones initially choosing to engage. I wouldn't expect them to have sound judgment or impartiality after they were attacked in the first place and fired at with a taser. Again, he absolutely didn't need to die, but he totally deserved it and the cops' reaction is understandable. If I ever attack a cop, wrestle his taser off of him, and fire at him as I run away, I'd like to, in advance, absolve the cop of all responsibility of shooting me in the back. I understand he wouldn't quote need unquote to do it, but it is totally acceptable if he does.