The lesson from this is that a gun report - or series of gun reports, or what might have sounded like gun reports, or ANY LOUD NOISE WHATSOEVER such as a police siren - would have dramatically changed the outcome.
i.e., in the face of an observed shooter in such a situation, ANYTHING which sounds like a firearm report or siren has the potential to change the outcome, removing control from the shooter and/or he/they controlling the shooter.
Think hard about that, as well as how it is possible that not a SINGLE non-USSS, local officer thought to ‘sound the alarm’ in the face of what was obviously either communications failure, bureaucratic wrangling/incompetence or, for that matter, conspiracy.
The fact that the local Police did NOTHING to warn of the potential threat and get Trump off the stage is DEFINITELY the biggest issue with the whole situation and seriously makes you question to what extent were “they” involved, obviously not the uniformed patrol cops—they just did not use common sense and do as you say-—just start yelling—”Shooter on Roof—Shooter on Roof”—Something—ANYTHING!
Its like when you go camping and a Bear rolls into camp—You yell—”Bear in Camp—Bear in Camp” You don’t zip up your tent and wait for it do hopefully move on—WTH.