Sooo, adventure tourists going to a live volcano have to be "protected" from any possible harm. What BS!
NZ has IMO become the ultimate nanny state- where did it all go so wrong?
IMO it comes down to whether the tourists were advised of the risks and signed that they accepted the risks. If they did, they have no right to expect protection from any and all risks, beyond reasonable precautions.
NZ used to be a country for real men, but that was long ago.