Damn.
It does sound like a near Professional level, exploration which everyone on the teams understood involved a much higher degree of risk than any "traditional" cave dive.
From what I read above it was inevitable that someone was going to enter that cave at some time because of the push for it to become an attraction. It sounds like the very best teams, with the highest degree of skill imaginable were doing this exploration, and even with that level of expertise something went wrong.
It truly sucks that a man lost his life, but as human beings we have always, and hopefully will always seek to explore, push ahead and discover our limits. There will be times such as this when a truly heroic explorer will not survive their exploration attempts, but it is only through ever testing our limits, and searching that mankind learns and moves ahead.
It is not for me to judge any person who knowing the risks, then does his or her best to minimize those risks, and yet still dares to push to go where none have gone before, to seek to expand our knowledge.
It does not sound like a life lost by taking risks for the thrill of risk, but of a tragic loss in the quest to learn, to explore and to pass that knowledge on to others.