My take: if they knew for a certainty that no other persons were in the cabin then burning it down, even intentionally, at some point, was not an outrage.
I want there and haven't seen the timeline so I don't know what was a reasonable point in time to do so.
But from reading what is available so far I don't see anything that shows a certainty that he did not have a hostage. And if it isn't established the authorities knew it for certain than this is pretty outrageous.
The problem is, and this is born out by studies, that the cops, especially urban cops, see three classes of people. a) themselves as above the law, b) perpetrators; c) civilians/victims.
I don't care about Dornor. He is a murderer. But what is in the back of my head is that if this guy had killed four persons unrelated to the police, I think their response would have been less urgent. I think the possibility of collateral damage to a civilian hostage was thrown out the window by the cops because this guy had killed cops.