Hmm. I don't know.
Over the course of the game, you played Bishop 7 times and your opponent played Bishop 11 times. That's basically the difference in points right there. Your opponent played Pirate Ship 27 times, you played Pirate Ship 21 times. Your opponent gained 2 treasures, 7 terminal actions, and 8 nonterminal actions, you were at 2, 5, 5, if I've counted right.
I'm not sure I see any difference in strategy between the two of you that would account for the difference. I guess I see a bunch of small things that went your opponent's way. His Talisman and Silver both got trashed later than yours. He had an earlier 5 for a lab, and had one lab more than you. He played Talisman more than you. You had that last turn where you didn't get a second Pirate Ship and so had to buy a Duchy instead of a Province to end the game.
The 5-vs-3 ships didn't make much of a difference. A 5 ship means you have to play two for a province, a 3 ship means he had to play 3 for a province, both happened pretty regularly. Except that one turn where you needed a second Ship for a province and didn't get it.
Yeah, I think I'll go with luck here, not much there between you two, IMO.