ASA Rule 7, Section 6, Item I states "When members of the team at bat, including those in the team area, OTHER THAN RUNNERS (my emphasis added) interfere with a player attempting to field a fair or foul ball", the batter is out. Since it was a runner that interfered with the fielder, the batter cannot be called out. Therefore, placing the batter on 1B after the interference call, since the ball becomes dead and the batter cannot be thrown out at 1B, was the appropriate call - especially since infield fly was not called.
MHO.