A lone Muslim gunman, in an ordinary cafe in a major city with the cops fully deployed and able to do a take out on him, and instead two killed with at least one other bullet wound, and you think that is a success?
It appears to be disaster.
I don’t think the Monday-morning quarterbacking is helpful. This will be fully investigated by police, by the Coroner’s Court, and by others. If mistakes were made, they will be identified. If lessons can be learned. But experts will make their determination after examining all the facts.
Sometimes a perfect outcome is not possible. From what I can see so far reported here, I can’t see any reason to assume that something went wrong, that something was done wrong. But it’s not impossible - and if so, that will come out in time.