Ruiz has the higher confidence in this rematch since he already stopped AJ on their first encounter. And this is an immediate rematch. AJ dared without a break nor tune ups which is very risky career wise. But I don't think AJ quit on their first encounter. It was the referee that stopped it.
Yeah it was the referee that stop the fight,.. in boxing especially in championship fight, its very rare to see a fight quit even though its very clear that he was beaten up so badly, one example I can give is Oscar De La Hoya, he quit and gave Manny a TKO, but its know a heavyweight fight however, its all the same.