Coaches Interference

[DonP]

Greetings!
Bases Loaded One Out
Batter hits a foul pop fly towards the 3B coaches box. Coach is oblivious to the fact that the ball is in his direction, thinks the ball went to the parking lot, has his back to the field looking for the ball over the fence. The ball is now coming down close to where he is standing, the third baseman is trying to figure out how to get around the coach to make the catch for second out. Ball hits the ground and is declared a foul ball.
Q's
Does coaches interference need to be intentional to be called?

If called, is the batter out, or is the runner closet to home called out and batter continues to bat with an addition to the strike count?

HFHS clearly requires a coach to "vacate" but ASA does not use the same wording. What are the umpires duties and responsibilites here?
Thanks for your thoughts