I looked not through the whole log, but I don't think that Thief was the key.
You played it only 6 times, the last 2 times you haven't found a treasure. The first time you trashed a Copper in turn 11, not a big deal.
You trashed a Gold in turn 12, a Silver in turn 17, and a Platinum in turn 20.
So I think the only real benefit was the Gold in turn 12, the Silver didn't make that much difference and the Platinum was maybe too late.
I think you may have won anyway.
But I have to agree, winning after you were 40 points behind is great and you managed that very well.