Owning the sideline?

[UNH IM Ref]

I was evaluating intramural referees at UNH last weekend and saw a particularly interesting call from one of our better officials who also happens to be a freshman that got his start long before college. He called a block that I immediately thought was a charge because the defensive player had given the dribbler 3 steps and enough time to change his course. After the game I brought up the play with the ref and he said that because the dribbler had established his path along the sideline's edge that he "owned" that sideline and the defense must give up their position to the runner on the sideline...

Was he blowing smoke or is this something that I've been missing? If it is a legitimate call then does it also apply to the baseline?

Thanks for your input.