I watched the video a couple of times and didn't really see anything out of line. I agree it sucks the dogs were killed, but from the sound of them it is most likely they were acting aggressive. There was another dog that was just trying to get out of the way and that one was fine.
As for the child, unfortunately most drug dealers have children. As we've seen in the headlines over the years the children are the biggest victims from their parents choices.
They may have only found a small amount of drugs, but no matter what your opinion on marijuana it is still an illegal substance. The tip that came probably didn't come in that morning and they organized the raid right then. They probably had surveillance going for weeks and a reasonable belief that there were more drugs in the house. It is not a simple matter getting a search warrant especially when a child is present.
In my opinion the officers acted professional in this raid. They didn't beat the man or were overly rude to anyone in the house. They informed him of his rights. No they weren't all smiles and nice to the man, but it's a high tense situation and everyone one those cops walk in there knowing that there is a chance they won't make it home to there families.
There are two people that are to blame for the death of those animals and creating the worst night for that child and it is the man and woman that live there.
Sorry so long, but I think these officers did a good job considering the circumstances.