You are supposed to give a step swipe, but no true help. Obviously there is context-specific of course.
B4 we get started, let me say, I'm not blaming lin. There are points when you have to stay in front of ur man. 1st rule, stop the ball. Stop the ball,trust your teammate to cover your man if you had to help. Then after the kickout,u find the guy ur teammate just left. You don't have to have all nba defenders to have a very good defense. You need guys to trust the rotations and not be afraid to give up their man.
The right way to do it is Lin helps, and another player rotates to his man, and another rotates and so on. Too bad the Rockets are not disciplined enough to do this so I guess Lin did the right thing.