Why was Pandya given not out after being run out on no-ball?

India's Hardik Pandya started walking off after getting caught off a Kane Richardson delivery during the second ODI on Thursday. Steve Smith, the catcher, threw the ball to Richardson to run Pandya out in case it was called a no-ball. Later, the delivery was called a no-ball but Pandya survived as he left the crease believing he was out.