Something to keep in mind is how video cameras compress the depth of field. While it appears that the crowd is sitting mere feet away from the president, it is more likely they were 10-15 yards behind him. With the ambient noise, it is likely the people sitting back there did not hear the first shots very well. It’s not really shocking that people would not “react” immediately.
Absolutely true. A normal reaction when something unusual happens is to “freeze.”
This happened to me when my hotel was attacked by terrorists. I heard explosions outside the compound wall, then gunfire and more explosions in the courtyard below my room. It wasn’t until a stray bullet entered my room that I snapped out of it.
“video cameras compress the depth of field. While it appears that the crowd is sitting mere feet away from the president, it is more likely they were 10-15 yards behind him.”
That is so true. From the front, it looks like they could reach out and touch him. But they’re actually very far away.