i believe this, the modern two-handed pistol shooting stances are a relatively recent thing related to the development of effective body armor afaik. ww2 tactics were to fire one-handed with your torso facing away from the enemy to reduce your target profile, whereas in modern tactics you want your front chest armor plate to be facing the enemy so that you have the greatest amount of armor coverage (you will almost certainly still go down if shot through armor but you are much more likely make it to a hospital, whereas getting shot while unarmored and in a ww2 rifle or pistol stance will get your heart and both lungs shot with one good center-mass hit. this is also why most militaries issue shoulder/upper arm armor also, because a shot through the armholes is devastating)

He’s a retired cop (MP), trained by a NATO military in the late 90s, so it probably is a result of American techniques.