Columbine happened less than 1/2 mile from me, many kids in my community were involved (mine were too young thank GOD).
The biggest lesson of Columbine that still reverberates in the community is never again will LE sit outside while kids are dying inside. The idea is to be in fast (as I understand they were in Bailey, within minutes they had SWAT and deputies in the building)
I would never second guess LE, they did what they thought best in all instances, but at least in colorado, you can bet that the authorities will be on the inside quickly, no matter what it takes. I think overall this is by far the better plan.
Columbine was a bit different in that you had mulitple shooters and a whole shcool building involved. Students were hiding and waiting to be rescued. Giving the gunmen time only meant that you were giving them time to find more victims.
If a gunman has everyone lined up in room and can kill them instantly then it is best not to anger him or set him off because there is no counter assault that can be effective against him. Since I don't seem to be sure of all of the details in this case then I won't make anymore judgements about it at this time. I am just pointing out that force is not always the way to deal with a disturbed person.