The prepping of the refs is a really interesting thought that I suspect was not enacted, maybe because the initial strategy assumed UConn gets the ball back with 5+ seconds and pushes it up the court to get an open 3.
Looking at the game film, as Christyn starts to dribble up the court, you can see Geno, outside the coaching box waiving his arm and calling for a timeout at the nearest sideline ref. How long it took for the ref to recognize that request and blow his whistle can’t be determined from the game film.