You can't claim exigent circumstances (I.e. immediate danger) and then proceed to systematically search 20 city blocks and then it turns out the dude was hiding outside their "perimeter". If people wanted to let them in, then by all means but if I opened my door and said "he's not here", the police unless they believe otherwise should move on since a) they have no proof he's even there (or they would have a warrant) and b) they can't prove that I'm in immediate danger (then there's no need for one)
Their sworn duty is to uphold the law and conduct their business within those standards. The burden of proof is on the officers to prove now that their 20 block door to door search fell into the immediate danger to each and every occupant in each and every house. They were shooting in the dark and hoping to hit something, which while it may be the best option they had doesn't mean they are above the laws.
As for punishment, I respect what they were trying to achieve, maybe some law refreshers for them. Mainly I want someone to hold their feet to the fire and show them that laws apply to them still.
ETA: there's no perfect solution in a free society, because the government is the one restricted, which may seem inconvenient but I would rather have more freedom and the danger associated with it, than more government control and the same danger. Notice what is constant in this equation? The danger,it will always exist, and therefore I will take the freedom.