I think that Heat did something interesting in Game 2 on defense. They decided not to care about defensive rebounds, but instead, to go with constant pressure on Spurs back court and close down passing lanes. That resulted in Spurs getting no less than 15 rebounds on offense (6 in Game 1), but making no less than 16 turnovers (4 in Game 1) that resulted in 19 points off turnovers.
Heat on the other hand, made only 6 turnovers and allowed only 2 points off them (15 points in Game 1).
19 points off Spurs turnovers that basically the final margin and Spurs guards had to always make decisions under pressure and usually, surrounded by 2 defenders and at least one of them taller than him, blocking his vision of the court.
I think that Pop needs to play small ball in such situations, to have much more ball handlers in such moments, but who am I to teach Pop anything...