I don't think Oscar ran because he was afraid of Tito, or afraid of getting hurt. I've never been an Oscar fan, but I have a ton of respect for him and he's gotten in the ring with everyone.
I think he just made a horrible tactical error, one that he probably regrets to this day, whether he admits or not. He was tired from being on his toes the whole fight, and he thought he had 7 or 8 rounds already in the bag. He thought Tito's only chance was to win by KO, so he gave him as little chance of that as possible.
It was just a bad mistake.