Posted by Nick Nalli over at the JFK Truth Be Told Facebook group...
Nope, this is a literally non sequitur.
The so-called "Harvard Educated CT" should ask for his tuition money back.
In the Zapruder Film frame of reference, V1 = 0, M2 << M1, and V2' is also small. So we can simplify as:
M2*V2 = M1*V1' + M3*V3
M1, M2, V2, V1', and V3 are either known or may be reasonably estimated.
In the Zapruder Film, we *observe* both V1' and V3 to be left-to-right (> 0). Thus, V2 > 0, and the bullet is moving left-to-right.
This is still "handwaving," IMO, but one can get the gist. The reasoning in the 2018 Heliyon paper is a more thorough and conclusive.