'The match isn't over until it's over' is one of the common sayings that are often said in cricket so there must be a reason why someone would have said it for the first time. That person would have probably seen some unreal performance where a team lost the match after most of the opposition supporters had left the stadium in disappointment.
Or, that person would have probably foreseen Sussex having an epic collapse against Gloucestershire in a run chase they were in complete control till 13 overs. Tom Alsop and Fynn Hudson-Prentice had added 70 runs in 54 balls for the third wicket as Sussex were cruising to an easy win.
Sussex needed 29 runs from 38 balls when an epic collapse happened. Tom Smith got Hudson-Prentice and Alsop stumped in the space of three balls. But the score still read 119/4 and the requirement was still less than a run-a-ball.