I wonder if his hold was ghetto-side-aim? It gets whackier by the day.
Most folks are right handed. A cross draw allows you to carry two pistols and draw both with the right hand. That’s faster and safer than drawing a pistol with the left hand and passing it to the right.
I used a cross draw rig in cowboy action shooting. It’s no big deal. Main rule was that you executed a pivot so that when the cross-draw left the holster, it was pointed down range.
You’ll also see it other Westerns.