It took 37 minutes from plan to prep to execution. That's not a lot of time at all considering it was no longer an "active shooter" but a "barricaded suspect" situation. A barricaded suspect can use hostages as shields, or bargaining chips by threatening to kill a number of them. Breaching a barricaded suspect is not the same as going in and taking down a gunman strolling the halls. Fact is, that's what they should have done long before the suspect barricaded himself with hostages. And its what Arredondo refused to order.