Edit: The only reason that I see for me losing is because I got killed on the boards and they had so many 2nd chance baskets. You would think with 17 steals and 30 assist with my opponent having 20+ turnovers would have been a winning formula. Maybe I'm wrong.
The net turnover differential was 11 (their 21 turnovers minus your ten), and they had five more offensive rebounds, so the number of extra possessions from those factors was just six, although you ended up with nine more shot attempts presumably due to rebounds out of bounds and fouls and whatnot.
The thing is, though, if you're running a FCP and you don't get a steal, the odds are good the other team will get a better shot. Since your OD is reduced (presumably on an individual basis as well as the team rating), your defense will be less effective and if my presumption that the reduction is individual as well as the team rating, it may explain why the opposing SG shot 6-8 from three against you, most of which were contested by your SG.
Basically, you're selling out for a steal; your opponent seems to be quite capable of not turning the ball over too frequently, and then taking the time to find the best shot opportunity and capitalizing on your decreased defense. Of course, you still could have easily won, as you had a one point lead and your PF at the line for two free throws in the last minute, but he missed them both and the rest is history.