Advantage/disadvantage and stopping the clock

[rsl]

Happened in a game last week. Team A up by ten, over a minute left. B is fouling to stop the clock, thinking they can come back. B1 gets lazy and grabs the arm of A1 in the backcourt, but A1 keeps going and now has a three on two opportunity at the basket at the other end and scores easily.

I didn't call the grab on B1 because advantage/disadvantage says let A1 go- there is no disadvantage. Coach B is upset and says if I don't call that foul, then his players will "have to foul harder to stop the clock and somebody will get hurt."

If we know a team is trying to foul to stop clock, do we (1) ignore advantage/disadvantage and call the foul, (2) call the intentional foul since we know they are stopping the clock, or (3) make a no-call like I did?