I was watching today's World Cup game between France and Switzerland. At the end of the game the referee blew the final whistle while the French team was attacking and right after a French player scored a goal:
The referee blows his whistle. And he's the Clive Thomas de nos jours, because a split second later, Benzema is lashing a first-time conversion of a right-wing cross into the top left from the edge of the area! He races off to celebrate France's sixth goal, but it won't count!
Does the referee have to wait for the end of an action to blow the final whistle or can they do it whenever they want? In case of the latter, why don't games end at e.g. 91:00, 92:00, 92:00... sharp?