That is not how to assess a defense situation. You'd get an F at the academy. You're responses are to be based on the information available to the target only. and he acted appropriately to the situation.
I think a lot of us said that he acted appropriately, inasmuch as he didn't hose the guy and he verbally defused the situation. This is a case of all's well that ends well.
Having said that doesn't mean we can't also give additional commentary. I think his actions were just fine, but the way he presented the situation never made the guy sound like a deadly threat. There's a long way from "blowhard in a bank line" to "guy who tried to kill me" and it sounds like the guy didn't come close to the threshold of 'justifiable'.