The regional Mezz Tour in NY/PA/NJ played by this rule 5 or so years ago (must shoot away). I was watching the hot-seat, and one player was straight in on the 9, but about a half inch away. He was about to jack up to make it for the win, when the other player stopped him. He said: "hold on, you must shoot away from the 9 because they are less than a chalk's width away." It was already 3AM, and the tournament director had already left. But the bystanders confirmed that that was the rule and it was covered in the player's meeting at the start of the event. The shooter was an A player, and the opponent an Open player. Both would have know if it was a foul.
I do think the opponent did the correct thing. He is a fierce competitor. Never cheats, but will certainly play within the rules, and plays jam up.