Not one person with a gun ran over to see what these people were so agitated about to see their point of view of the shooter.. just boots on the ground keeping eye level?
Listen to the interviewer.
The shooter knew a blind spot ahead of time
Cops were near by the building supposedly the shooter was on
Secret service sniper meats had eyes on the Trump supporters pointing at the shooter but believed the angle of the roof blocked line of site to shooter, a blind spot that was either lucky, planned, or discovered