We respect the people who are given the job of dealing with hostage sieges, such as the recent tragedy in Sydney. They have to make tough and quick decisions. We now need to spend some time looking at the process, so that we can do it as well as possible next time.
When we think of lone nut cases with weapons we remember the bad outcomes. The lone gunman at Port Arthur is the one that comes to Australian minds. However that wasn't a hostage situation. The lunatic then was shooting people at a distance that he had not met. Most single person hostage taking involves explosives and the threat of a suicide bombing, or it involves a male with family members. So this was an unusual case.
When a team of hostage takers are involved then the whole thing is more practical. They can take turns sleeping. They are likely to have a plan and specific objectives. They can provide moral support to each other, plus the implied threat of violently punishing any backslider. The whole thing might even be relatively sane, without being less bad for that.
Since there isn't much time when the action starts, we need to have a small number of people in the country who know a lot about these various situations and how they have panned out in the past. The little point that I would like to get through is this:
The people who end up making decisions need to know about good, as well as bad, outcomes from around the world. The good outcomes don't stick in the mind. The good outcomes aren't as well reported. It is an easy mistake to overemphasize the possibility of bad outcomes, and then take overly aggressive action. I'm not saying that is what happened in this case, though my instinct is that someone sane enough to be given parole would find it difficult to shoot people he had been dealing with for many hours.
The importance of negative results has been recognized in medicine where all trials must be registered before they start. This stops drug companies from running multiple trials and only reporting when benefit is shown.