Very simple: in the last five minutes Gonzaga became tentative and was more concerned with pressure instead of taking advantage of Tenn's over-playing defense; hence the steals, shot clock violations and poor buzzer shots selection. Zags relaxed on post defense and kept giving up the and ones.
However, Tenn's incredible foul shooting combined with Zags missing two front-end one and ones made a huge difference.
Athleticism and coaching experience also had an influence on the outcome. Hats off to the rookie coach, her team performed well.