In the final portion of the video (Super Zoom at 1/4 speed) if you look at JBC's back as he rolls over I think you can see two things:
1. Red on the upper rear portion of his suit jacket - don't know if it's blood or rose petals
2. On the lower right rear of JBC's suit jacket you can just make out a white spot - which may be a bullet entry hole.
Yes, I was going to comment on point #1. I too see a "splotch" of red on his suit jacket; but that, of course, likely from his own wounds and not from JFK's wound.
Why would the Connally's, Greer and Kellerman all duck down after that third shot? On the first two shots we don't see them ducking; but on the final shot we do. Why? What made them duck?
I don't see #2 but I'll look again.