Bronson shows McIntyre looking at Hickey az Hickey fires.
And Bronson shows McIntyre looking at jfk after Hickey fires.
So, McIntyre did not see jfk's head blown off.
Poppycock!
The Bronson film is too poor quality to make any possible distinction of ANYTHING McIntire or Hickey are doing when the film is blown up or otherwise enhanced, plus the film ends too abruptly after the fatal shotyto capture any such things.