Let's grant that Zapruder filmed the limo turning into Elm.
Wrong.
IIRC, the limo was already about 70 feet down Elm Street when Zapruder resumed filming at Z-133.
Nothing of any consequence happened until the limo was way down Elm Street.
Probably wrong.
The conscious and nearly synchronous reactions of seven prime witnesses (including JFK, Jackie, and JBC) to the sounds of Oswald' first, missing-everything, shot indicate that it was probably fired at "Z-124," half-a-second before Zapruder resumed filming.