Imposter: castling wasn't the problem. After 25. Kh2
click for larger viewLe fumbled with 25...Bd6+ (which is still ok as wordfunph shows, if followed up properly) rather than playing the obvious and better 25...Nxf2 (threatening 26. Qh1  with a mating attack) 26. Bxf2 Bxf2 and if anything he has the better game, or at the very least easy equality (eg: 27. Qh8 Qe8 or best of all 27. Qxh7?? Bc6 mops the floor with White). black's losing move seems to have been 25...Nxg3??, destroying all his threats and options, and obligingly building a brick shelter for white. this sort of suicide of the lesser player snatching failure from the jaws of victory happened in the US women's championship earlier this year in A Zatonskih vs T Abrahamyan, 2011 a rapid game tiebreaker where black dropped her chance to clinch the national title at this position: 
click for larger viewhad black played here the simple 65...Kxb3 the US title was hers. Instead she played 65...Bxh4?? and after 66. Nf5, the game was drawn five moves later. Black went on to lose the extra tiebreak match. for white is completed a great comeback from the bottom of the table. | 
g3
(0.57): 25...Nxf2 26.Be5 Ka7 27.Bxd6 Qxd6+ and GM Le Quang is ok.
