I wrote a complaint to Korean Air. They responded as follows:
Thank you for contacting Korean Air.
Regarding the case, we have found that there was a miscommunication between the captain and the cabin crew. Ministry of Land, Infrastructure and Transport of Korea is currently under investigation on this, and we are fully cooperating with them.
We would like to ensure you that we will continue to put full effort to provide a safe and comfortable flight experience to our valued passengers.
Sincerely,
Customer Relations
Korean Air