Mueller presents this position from Georgiev -- Berkes, Tallinn 2016.
White to move
Georgiev played 79.Ke5? and settled for a draw after twenty more moves. Mueller points out that after 79.Kg5, White will be able to put Black in zugzwang. ChessBase News (24 January 2016) shows that 79.f3 also wins. CB News also displays Georgiev's tweet, where he notes that he missed wins both against Berkes and against Gelfand.
Additional information, if accurate, is available at Chess Bomb. Playing through the game score there reveals move times. According to Chess Bomb's times, Georgiev spent six seconds on 79.Ke5 and had only 43 seconds left on his clock at the time. Berkes had 1:36 left.
How many players at any level could have found 79.Kg5 or 79.f3 in six seconds?