"(One of those two security officers was on the 32nd floor nearly immediately, because the pair had seen some glass fall from the window, from there vantage point below that window, at the time of the shooting.)"
I had not "heard" that before. If true, that would explain alot.
Actually that security guard is on film. I saw it by the following evening. Guard was already wounded but SWAT and he coordinating in video from Security Guard body cam.
Guard was inching towards the shooter’s room whispering to SWAT where the cameras were that shooter had placed in a dining table outside the room, and SG reported that he had already cleared neighboring rooms to shooter.
Guard asked SWAT to signal him before they broke through the stair well to the hall way on 32nd, to avoid a “blue on blue”.