Also it's very likely if the human played stronger in the last match, the computer also would have stepped up. Computers tend to sacrifice points (i.e. "big leads") for assured victory, so unless the human is stronger than the computer, you cannot know it's true potential.
That's a common strategy in human game play and sports as well. It has been observed many times that humans on their own in regular sports do much worse than doing the same in competition against a somewhat stronger party. As they say: one boat is a cruise, two boats, it's a race.
