You're being extremely loose with the term "very early" and then applying that to differing points in time. And a possible 10 frames is more than a 1/2 second. These are the lengths you are forced to go when pushing this Max Holland concoction.
Forget Max Holland and his "Z-107" missing-everything shot, Comrade Stormtrooper Storing.
The fact that all of the people I mentioned in my last post consciously and quickly reacted in a non-"startle"-like manner between Z-140 and Z-150 suggests that Oswalds fired his first, missing-everything, shot about a second earlier at "Z-124," i.e., half-a-second before Zapruder resumed filming (after a 17-second pause) at Z-133.
D'oh ......... D'oh ......... D'oh!