Where do you think this very early 1st shot, (before Zapruder filmed the JFK limo), was hatched from? This started with Holland and that cockamamie stuff of his regarding a bullet striking the signal light support beam. There is zero evidence of a bullet striking that signal light. If You or I were to propose something of this nature, with zero evidence to support it, would see us getting laughed off of this forum. Holland somehow gets his schtick broadcast by National Geographic and guys like Gary Mack/"Sixth Floor Museum" are falling all over themselves to support it. Any wild scenario supporting a "lone gunman" is granted free rein with a cheering section to go along with it. You promote a "conspiracy" and you are immediately forced to run through a gauntlet.
Dear Comrade Storing,
Holland did find an old painted-over shallow dent on the top of the mast arm near its juncture with the signal box.
I thought you knew that.
Regardless, based on the fine work of Roselle and Scearce, I think Oswald fired his first, missing-everything, shot about a second later at hypothetical "Z-124," i.e., half-a-second before Zapruder resumed filming at Z-133 after a 17-second, film-saving pause.
-- Tom