? So, the ultimate stopping point for Langdon's thinking is...

I think his point is more training and familiarity is needed with whatever pistol you carry...and if you're not competent and safe with a gun with less room for error, maybe you get the Barney Fife rig until you're more competent.
A University of Cincinnati cop popped a dude in the head and killed him last year at a traffic stop. The Sam Dubose dude was certainly riff-raff, but looking at the video, it does not seem he did anything that warranted getting shot for. I suspect the cop did not mean to shoot him in the head, I suspect he wanted to draw and point the gun at him and had an ND. https://youtu.be/Z0c...jrSjyc?t=1m50s
UC police switched from SIG 229 to SIG 320's shortly before the incident, according to this article. http://www.cincinnat...ting/32339335/
It would be interesting to see stats on ND's with the various type actions