In a doubles match, Erica hits a lob. The ball goes over the opponent's head, and the opponent starts turning around just as the ball is bouncing. Neither Erica nor her partner could see whether the ball was in or out, and the opponent’s partner never turned around. The opponent calls the ball out. Erica says that since both opponents’ backs were turned, that the ball should be called in. The opponent says that the ball was out and it is her call.
Who is correct?