Can someone explain the reasoning behind the game ending with 1 second left on the slow motion replay clock.

In years past, in most sports that keep time like basketball and football, you have to allow the scorekeeper time to react to the referee’s signal to stop the clock. The ref has to be allowed time to react as well as the person in charge of the clock. There is an extra second or two runoff that shouldn’t be on dozens of plays every game. 2 seconds would be more than a reasonable amount of time to get the clock stopped. They explained the rule correctly, but did a poor job of explaining why the rule exists.