I've noticed that LB/RB doesn't always work and is too slow. Another thing I've never really noticed until today is that you can't intentionally foul a player if they're backing down even when intentional fouling is set to auto.
Here's a clip of my opponent exploiting this.
http://xboxclips.com/Lo6IX/706210b9-...a-30ceda0c668b
Notice the CPU Paul George sprinting into Jason Terry and me holding X and having my player do nothing then spamming X and having him swipe at the air. My opponent inbounds the ball to a bad freethrow shooter and he gets bailed out.