Agreed and here's another aspect that occurs to me.... Agreement on a timeline for what happened seems to be an every changing thing but it sounds like shooting started 6 to 8 minutes after the MB security and maintenance guys were shot at. Then shooting out the window went on for 10 1/2 minutes. Not sure what happened to the maintenance guy after the shooting started but apparently the security fellow was still there when the police arrived. By my reckoning, this means that if police were there within 20 minutes, this means that they were never actually on the floor when there was any shooting going on out the window... in fact, the security guy could have reported to them when they arrived that "good to see you.... just so you know, the shooting stopped 5 minutes ago."... or something like that. It would have been interesting to be a fly on the wall at that point to find out what they cops were discussing as to what they were going to do but in the end, their delay in breaching the door really didn't make any difference with respect to what Paddock was doing in the room.
I've mentioned here before that I've wondered if they sent a drone up the side of the building to look into the window and could see that Paddock was already on the floor. The other possibility is that they have a robot with a camera that went down to the end of the hallway to look through the holes in the door or using other heat sensing technology to ascertain that there was no movement any more on the other side......at that point, they went more slowly only because of the possibility that someone else could be hidden motionless in the room in a part that couldn't be seen or they went slow because of the fact that the door could have been booby trapped. I'm going to bet that they already knew that Paddock was dead very shortly after arriving on the floor and definitely long before the door was breached. I suspect that one of the reasons we are hearing so little information (and conflicting information) is that they don't actually want to reveal what capabilities they all have at their disposal.
Shooting may have occurred prior to the security guy showing up and he did not hear the initial volley.