What did black miss here?


ok, latest thoughts:
25 .... Bxh2+
26 Kh1 Rxf2
27 Rc3 Qe7
With dire threats on the dark squares, the White Knight cannot return to f3 because the White Rook needs to defend the g3 square.

For my money you haven't looked at the crital line yet (perhaps, I'm missing something):
25 .... Bxh2+
26 Kh1 Rxf2
EDIT:
Yes Kh1 a typo on my behalf

So after 25.Bxh2+ 26.Kh1 is the only move.
Ok (Kh1 as I gave in my original post), so what after 25.Bxh2+ 26.Kh1 Rxf2 .... looks like White is doomed.

Ok, tnx, I was unaware that Ng4 opened line for Bishop too.
But what about position after 29.th move.

Ok, tnx, I was unaware that Ng4 opened line for Bishop too.
But what about position after 29.th move.
I think Black has blown it after 29 Nf4!. The threats along Black's back rank and the promoting pawn are mortal ones, also the Knight on f4 and the Queen on a7 cover all the vital squares in defence. I've looked at some of the sacrificial lines for Black but they all seem to come to nothing.