Always shoot the hostages. They should be held responsible for letting themselves be taken hostage.
Either you're willing to shoot the hostage-takers through their human shields, or the situation will escalate, generally through more and more hostage situations and thus more incidents of hostages getting shot, until it's intolerable and you're forced to shoot them anyway, however unwillingly. If taking hostages results in getting ransom instead of getting merked, then your society is hostage-positive.
NB: the hostages are not still alive. Taking a hostage is properly considered murder. In some rare cases the hostages may be resurrected, but until that resurrection, they are already dead. When you shoot through them, it is not homicide. If a hostage-taker gets anything less than mass murder at trial, you're doing it wrong. Even if all the hostages managed to get resurrections.
The hostage could have fought back. Ultimately they could have fought enough that they died, resulting in no hostage and thus no hostage dilemma.
In other words, the hostage dilemma is the hostage's fault and they deserved to be held hostage. Since they deserved it, they should be held responsible for it.
Allowing yourself to be taken hostage is a crime, and, should it not be necessary to shoot the hostage-takers through their human shields, the hostage should be liable for criminal penalties. Use strict liability: if they were drugged, well, they shouldn't have let themselves get drugged. Secure your water supply or whatever. Responsibility is not conserved; it has a minimum at 100% but can go arbitrarily high. Just because the hostage-takers are 100% responsible doesn't mean there isn't an easy 100% responsibility to share out to the hostage. Indeed further down it will easily reach 300%.
Facing criminal punishment for letting themselves get taken hostage, the hostages fight back. Knowing the hostages are only going to savagely fight them, the hostage-takers don't bother to try to take hostages. Result: penalizing hostages prevents attempted hostage situations.
Objectively speaking, responsibility is about, ultimately, deterring crime. Punishing the hostages prevents hostage situations. Hence, we conclude the hostages are responsible for the hostage situation, and should be held responsible. We would so conclude even if we couldn't immediately see what hostages could do about it. For the sociological engineer: if you don't know who to punish, try punishing everyone one at a time, and keep the one that deters as intended.
Further, lawmakers who refuse to punish hostages should be held liable for all hostage situations. They are hostage-positive. Ding, 300% responsibility. These lawmakers are encouraging it on purpose. Should face the same criminal penalties that hostage-takers face. If they don't face (and suffer) penalties, then you have dispositive proof that you don't live under rule of law, and should disrespect the law accordingly.
Perhaps the divine justice is shown to us by the fact hostages are already dead. Given they are dead, issue their death certificate and start the inheritance procedure. Dead folk can't own property. Dead folk have no rights at all. They were resurrected, but so what? They don't value their lives enough to avoid getting taken hostage, why should society value their lives more than they do? It obviously shouldn't. Re-allocate the wealth to those who may still be willing to secure and defend it.
They can keep their jobs, I suppose, but they would have to be paid in cash. You can't put a dead person's name on a bank account, after all.
This principle generalizes. The victim should be blamed. They are in fact responsible enough.
In other words, if someone gets conquered, they deserve to get conquered, and if this inconveniences you, it's very much their fault and you can strip it out of their hides. Never impose costs on yourself for the benefit of a conquered people; this only encourages the conquest-positive. Don't be an enabler. Do to them whatever happens to be most convenient for you. Don't cooperate with deviants.