Point blank is where the vertically curving flight of the bullet crosses the line of sight, which is a theoretical straight line. Since the bullet will cross that line twice there are 2 point blanks, minimum and maximum.
Where each point blank is along the line of sight depends on how far above the bore the sights are and tha ballistics of a particular round. Minimum point blank is not neccessarily very close to the muzzle.
In this instance, seeing that the distance of the shooter to the target was about the distance across an ordinary LI front yard, I’d say the ‘point blank’ I used and the one you defined are about one in the same..............