Strong play! Blacks 19th move is not a Novotny since there is no effect on the closed bishop diagonal f1-a6 as is required after the rook is captured by the queen. It is only effective because the rook is protected by a knight which is commonly not the scenario for real Novotny moves!
Brilliant sequence for black
However, thank you so much for the comment
Perhaps it is more useful for you to know that blacks 19th move is called an interference move, a popular character on the composition circuit
. For an interference it is sufficient to disrupt a single line of a single piece (here the white queen).
Oh my gosh that is savage brilliancy!!!! That is disgusting! Is this a real game?!
It says nothing about the puzzle and everything about the distance you have to go in chess. GMs play moves like these for breakfast with sleepy eyes. You want to see a savagely brilliant game move? Then look a second at white's move 26 in a game between Ivanchuk and van Foreest:
https://www.chessgames.com/perl/chessgame?gid=2416368
p.s.: the rating shown above is the FIDE elo, it's neither from chess.com nor Lichess.