Ahem... a little devil's advocate here...
Nik isn't ignorant of standard cave diving practices, standard ascent rates, or other common diving practices any more than Evel Knievel was ignorant of standard motorcycle practices. He's just doing his own thing in the limited environment of the tunnel to the piano room at Vortex, probably the safest cave (by the strict definition of "cave") on the planet. (And, as earlier posts in this thread attest, one of the most treacherous caves on the planet if you press on past the crack). Other than setting a very bad example for new divers, if you look at his actual profiles and practices - and if you have a firm grasp on decompression theory - though at first blush they seem way out of bounds, you won't find anything with much in the way of elevated risk to hang any expectation of an untimely demise on at all.
For example, in
this video at about the 2:48 mark he makes a 50' ascent in right at 10 seconds... 300 fpm. Horrors! But under the circumstances... total dive time of under three minutes, most of that tooling around at 20' with probably all of 10 seconds at 50'... no big deal.
No, Nik's just not doing it "right" - but he's having a great time doing it, and his margins are a great deal more than many of y'all are giving him credit for.
Rick