Everything in this story screams "WTF" from caver's perspective.

Unlike climbing, you don't solo caves, and the Veryovkina cave is a Chomolungma among caves. The deepest I've done was ~400 m underground and it's hell of an exercise, requiring fitness and skills.

And this guy went alone down to -1100 m totally unprepared, with two ascenders weirdly connected with a carabiner, which guaranteed he won't be able to ascend anything. Most likely he didn't even test it on a rope.