After his AO match and with his current confidence, it would have been pretty silly not to think Waw had a very serious chance to see the final. I think if he didn't get physically troubled from start of 4th set he'd have closed it there.
He's a mental midget in big games, he has proven that countless times. Can't close out matches, 4-12 ATP finals record. Leading by 2-1 sets and still losing was all but typical for him.