‘they were in on it and told to stand down.”
-—I’m afraid I’ve come to that conclusion....and their admission that they “froze” is part of the bargain to both give them immunity and offer themselves as a temporary (moving) target of scorn, meanwhile taking the focus off just about everone and everything else. The longer this goes on, the clearer it becomes that something explosive still needs to be hidden, managed, and allowed to die. NO ACCOUNTABILITY.
Certain persons had to complete certain tasks and clear the scene before the police could be permitted into the rooms. The people who plan and manage these operations are counting on the effectiveness of the chain of command.
If command and control was less effective, and cops were prone to attempting intervention into wet operations in contravention of orders, planning and executing these operations would be greatly complicated by the necessity of having a robust contingency to intercept and neutralize any Rambos. No winners in that scenario, are there?
If you want to stop a Las vegas in progress, you need to match (or preferably over-match) the lethality of the team which is executing the operation. Police forces operate in a completely different realm.