If he brought the ladder in on the 13th, and nobody noticed him or stopped him, it wasn't a coincidence. It was deliberate. And how does a civilian fly a private drone over what is supposed to be a secured site two hours before the rally began? To me that's proof that no law enforcement on the ground gave two shits about securing the site, or were told to stand down. Anybody that has been involved in security, securing sites, searching grounds looking for potential problems, etc., would not have missed the obvious.
The story says that he bought the ladder on the 8th. There are maybe a half dozen Home Depots closer to Bethel Park than the one in Butler. There’s also at least one on the way to Clairton.