The F/O replied that as it was his leg
Misplaced or perceived authority on the FOs part. He might be pilot flying but that does not confer any extra authority nor does it remove authority from the pilot in COMMAND, ie. the captain.
Notwithstanding that but better CRM from the captain initially could have prevented this situation. However, better CRM from the FO following the captains intervention would also have prevented the same situation.
A similar situation occurred when I was an FO. It was a simple case of accept the captains decision but get my suggestion in earlier the next time something happened!