Yeah I was just looking it over and considering the Gardens option. I guess I tend to automatically ignore Gardens when there's decent trashing.
The game lasted 16 turns, and we both finished in the 20s for number of cards, so I don't think Gardens would have been a good option.
I'm not sure that Gardens is the right play here, but without knowing exactly what happened, this is probably misanalysis. First of all, obviously, if you're going gardens, you'll have a lot more cards than if you're trashing. Furthermore, the game will either last much longer, because it takes much much longer (generally) to get 8 provinces than 4-5, or shorter because the gardens player has cut the legs out from under his opponent.
Having said that, turn 16 probably means you could expect maybe 5 provinces and a duchy (that's a bit generous I think), no estates, for the provincing player. But I would expect that the gardens player could beat that score by that point. Again, not entirely clear whether this is good in the long run, but if all you got was by 16 turns, gardens seems quite reasonable.