I have to agree with Mike in VA about the serving of the warrant. Had that been the approach, the whole affair had a much better chance of ending peacefully. The ATF escalated the use of force in that situation, even though the necessary suprise element for a dynamic entry had been completely blown.
When you make a dynamic entry of a structure that large, with that many armed enemies, you need good intel on the people and the layout of the building. I doubt the ATF had either. They were just waiting to prove how big and bad they were and underestimated their opponent.