LOL. You're like the stereotype of a bad cop, asserting unearned authority, completely full of shit, more interested in covering ass and maintaining you're "in charge" status than anything else. Falling back on whatever bullshit "procedural" excuse you can come up with after the fact to justify failing completely at your job.
The cops here have been lying from the start, the "factual" claims (LOL again) they were making have been changing daily and now they're apparently not talking at all to the press or even to official investigators, so your entire premise of being the guy in the thread going with "the facts" is bullshit just on that basis.
The claims that the situation had changed from "active shooter" to "hostage/barricade" are similarly bullshit since this apparently happened within 5 minutes of cops arriving on scene (again, if you believe what the cops are saying), but there was apparently no command/control on scene even to make that determination.
They didn't do their jobs and they didn't follow their training/guidelines and they knew it and that's been obvious from the start since they've been lying from the start (even taking into consideration "fog of war" issues).