Was it right to default Medvedev for hitting spectator with ball?

Daniil Medvedev was defaulted for hitting a spectator with the ball during his semi-final with Novak Djokovic at the China Open, but was it the correct decision or should he have been able to continue playing?

Medvedev was trailing Djokovic 7-5 5-3 and had lost a point when he hit the ball coming off the wall.