Quick draw BART cop uses asinine defense

Recently I have read in the Austin American Statesman that Officer Mehserle's defense, the one who shot and murdered Oscar Grant of Oakland on a B.A.R.T. platform at pointblank range, has now pleaded accidental murder and inexperience, because he really meant to pull his non-lethal taser gun instead of his service revolver? What kind of country are we living in when an officer of the law who is supposed to "protect and serve," and is payed to do so by the taxpayers of his/her respective state does not know the difference between lethal and non-lethal force, or know when to use either force when dealing with an unarmed suspect? This attempt at litigation is a travesty, and an insult to our intelligence, not to mention disrespectful to Mr. grant's family and loved one's.