This is the famous 2004 "egg incident" in Ivano-Frankivsk, when an opposition activist threw an egg at Viktor Yanukovych in public.
"Yanukovych collapsed to the ground, groaning and clutching his chest.
Initially hospitalised in intensive care, he recovered within hours and went on television to say he felt sorry for the 'wayward' youngster who had thrown the egg." (BBC News)