Not a pistol. The gun in the picture is a stainless Ruger Mini-14 with an aftermarket side-folding stock. That particular model looks to be the Butler Creek version. The Mini 14's have an 18.5" bbl, and a "Short-Barrel Rifle" is anything less than 16". Yet another instance of "Truth in the Media."
Not enough information to go on as far as the Casad reference. My guess is if the guy was talking loud enough about his gun, calling attention to it on his own, then who knows if he volunteered all of the information and the weapon as he was approached in a "voluntary conversation."