I think you major problem is, you've badly underrated your opponent. He appears to have alot of very well rounded players, with skills that help but don't necessarily show up in the player ratings.
Let's have a look at them.
The bloke he played at PG is a bloke that has pulled 16.5 ratings at SF. That suggests a very well rounded player. I wouldn't be surprised if he had a huge amount of IS, and he was one of the keys to him winning, as he managed to score at a pretty efficient clip. Going against Than Nan, with only ressy IS, probably gave him a mismatch there.
His SG has managed to pull 13 ratings at PF, and 16 at SF. Again, suggests a very well rounded salary efficient player. You kept him pretty quiet though.
His SF looks like a gun - pulled 20 ratings at SF, and despite only 80K wage, has played plenty of NT games in the uber competitive Italian NT.
His PF has almost pulled 20's at SF before, and has pulled pretty good ratings at SG - 14s (for comparison, Wayne's outside skills are pretty good, and he only pulls 10s at guard spot). I'd suggest he has a huge amount of outside skills. Another bloke who has played plenty of NT games for a decent euro team.
His C also is capable of pretty decent ratings at SF. Though he is probably the weak link in the team.
All up, I would have backed your team to win comfortably with a LI. But the problem with base is, once you come up against any sort of decent outside D, your guards will just chuck bricks unless they are insanely good shooters. And that's basically what happened - your guards chucked bricks, and your bigs were efficient, but just didn't get it enough.
Bad luck. But I guess now you can sell up and have a crack again next season ;)