Question about foul on inbounds play

[Damian]

I think you missed the scenario. The screen was setup on the person guarding the person throwing the ball in. When he runs the endline, the defensive player will run along too. The screen would not be blind as it would be from the side.

So there would be an advantage in this particular case to having one foot OOB since the person he defending is already legally OOB.

Thanks to all for the good comments.