That makes some sense, but I'm always reluctant to correlate FTA to FGA to find a theme. If you get fouled and go to the line for 2, you don't get a FGA (whether a 2 or a 3) so the disparity in FGA grows with each trip to the line. The Pistons also got a lot of second chance opportunities that account for the overall disparity. And the Pistons have, seemingly, made a conscious effort to not try many 3's against the Spurs so far (around 6 per game), so they're going to get a lot more 2 point attempts.
I try to stay fairly objective about the officiating, but I haven't seen any huge disparities. I thought the FT disparity was vast, but I also noted that the Spurs got to the rim far more easily in Game 2 than I ever thought they would against Detroit, which suggests to me that, despite the FGA disparity, they were attacking the rim far more aggressively than the Pistons were.