The problem as I understand it, is that they wanted to do the raid at the drug house as a no-knock raid, and needed to raid all the places at the same time.
The warrant was valid.
The question is not if it were legal, but rather if they were prudent.
45 seconds to a minute after midnight is not much time to wake up, get out of bed, and answer the door.
Then, when they did not find any evidence of wrongdoing, the manure hit the rotary air mover.