But there's a lot going on in the motorcade they came to watch, also. Reverberation was being sensed by then, too. To me, you seem to compare their situation with sitting in a windowless room with no distractions and having only to process a rifle being fired overhead.
A few years ago, there was a stadium full of football fans in France who kept watching the game while explosions occurred just outside.
People don't always behave in unison, or conform to predictable behavior, in a crisis. They generally compartmentalize things. Like you do with reality.
Las Vegas Mass Shooting
"‘There’s a shooter!’: Body-cam video shows officers passing unaware casino-goers during Vegas shooting" ( Link )
"1 October body camera video shows people sleeping in rooms unaware of active shooter" ( Link )
Mr Organ...Your cites are totally unlike the situation that BRW and Harold Norman would have experienced.... Allegedly they were only a few feet from the muzzle of a rifle that was being fired above their heads..... IF that had actually happened thirty seconds before the photo was taken we would not be looking at two men are showing no sign that three ear shattering blasts have occurred just a few feet from their heads.
BRW is displaying a puzzled interest in something happening down on Elm street....And Mr Click - Clack- BOOM , Norman isn't at all interested in anything on Elm Street....He appears to be looking at something on Houston street.... He most certainly isn't cringing away from three ear shattering muzzle blasts, and he most certainly is NOT interested in objects dropping on the floor above his head....