The presence of a second sniper reminds me of the Jack Reacher movie, which is based on a novel I believe. In that, even the patsy who thought he was "the sniper" doing the shooting, wasn't aware that there was another professional sniper on the bridge, who did the actual killings. The controllers knew that the patsy was a lousy shot and will miss most of the targets. But again, this might be a very common playbook being used by the FBI/CIA, whoever is orchestrating this thing.
You can approach all of these planned assassinations with an assumption that there are patsies and there is an actual sniper/shooter who has been tasked to finish the job. If there was divine intervention, did anything happen to the actual sniper apart from Trump turning his head. Perhaps, the wind blew just a bit more or less to deflect the bullet enough. All possibilities are on the table.