I'm talking about the Y button hopstep backwards. Or the one where you are running and you push the shot stick away from the basket. Both end up in similar jump-back-shoot animations, but the first one is the one I used the most to try to get behind the 3pt line without actually running back there (when i first played 2k11, I did sometimes run out of bounds, even with the force field).
(just to clarify, in this post i'm talking about the corner 3 area.)
I think the problem is a bigger issue in that the corner 3pt area in a video game there's a lot less room for error than in real life. I'm 6'2 and i can easily run along the sideline to the corner 3pter, turn around and run back without stepping out of bounds or on the 3pt line. But in video games pasts (not just 2k series), it seems like you had maybe 2-3 pixels to work with before you either step on the line or step out of bounds. But in reality there is a lot more wiggle room there. The force field kind of balanced that out, for if i tried to tap my controller slightly in any direction, i risk my guy doing an animation in which his foot steps on the line.
Have you tried doing triple threat out of the corner and seeing if it results in steps on the line?