43.u14 was a successful bluff; rhop EXPECTED to lose, so resigned, instead of playing 44.w23 which wins easily. However, Nagy still DESERVED the win, since after 43.v24 securing the bottom, black is obliged to block the u14 connection with, for example, 44. w14 after which white will still win, though it can be tricky. I see 45.s15 threatening connection at u14; black blocks with 46.t13 and what can follow now is 47.q1648.o13 to block the connection, and 49.r1450.p1551.s12 does it.