Interesting read. I have taken the full dunk tank helicopter egress training for working on offshore oil rigs. We didn't have the tethered harness bit, but did have to open a door/hatch and climb out while upside-down underwater. I think there may have been a quick-release seat belt, but I'm not completely sure.

That training didn't bother me much, I think mostly because I had grown up swimming daily, have been surfing, snorkeling, and SCUBA diving, and am pretty comfortable and confident in the water. It took a while for me to realize that many people are deeply terrified of being dunked in water, and may panic and do any number of strange things. It makes me wonder if any reasonable amount of training can really make you ready for that. Or if I would also be in way over my head [sic] in an actual crash - it was occasionally pointed out that in actual over-water helicopter crashes, usually everyone dies regardless of what sort of training is involved.

It does make it seem a bit crazy that they're flying random tourists around like this without even a practice run at how to detach their harness tether or knowing whether they can even swim at all. The release method being to pull out some sort of knife that's supposedly attached to the harness and use it to cut the tether seems a bit crazy too. The author has no idea exactly what kind of knife or exactly where it is, which says a lot about their pre-flight training. How many people will fumble the knife, cut themselves, stab random things, etc trying to cut a tether while in a rapidly sinking helicopter? They should have some sort of quick-release that's easy to grab and uses one simple motion, and that they practice releasing several times.