"I have acute pancreatitis and can't come to work"—store owner tells part-time worker, "10% wage deduction," then fires them [What do you think?]

[Financial News] A story about a part-time worker who reported being unable to come to work that day due to suspected acute pancreatitis and was told by the store owner, "I will deduct your wages," has sparked controversy.

Recently, a post titled "I told them I couldn't come in today because of acute pancreatitis, and I got fired" was uploaded to the online community dcinside, along with a record of text messages exchanged between convenience-store part-time worker A and store owner B.
In the messages, A apologized to B early in the morning, saying, "My stomach hurt so badly early this morning that I came to the emergency room," and explained that they could not come in to work that day.
After receiving intravenous fluids for suspected acute pancreatitis, A was found to have an abnormality during an abdominal ultrasound and was advised to undergo a CT scan at a university hospital. A was traveling there with their parents. Acute pancreatitis is a severe emergency condition that causes excruciating abdominal pain and can become life-threatening by leading to shock or multiple organ failure.
However, store owner B responded coldly. B said, "Are you notifying me on the same day? Are you saying you're quitting?" and informed A, "I'm sorry, but I have to deduct 10% during the probationary period. I'll deduct it from next month's paycheck."
B continued through the messenger, saying, "I clearly told you during the interview that absences like this would absolutely not be allowed. Taking care of your health is your responsibility," and demanded, "Telling me a few hours before your shift is a notification, not a discussion. Are you going to take responsibility for the losses?" B also reiterated that 10% would be deducted from both the August and September wages.
However, this may constitute a serious violation of current law. The Labor Standards Act requires employers to pay workers their wages in full and prohibits contracts that predetermine penalties or damages for breaches of an employment contract. The 10% wage-reduction provision for probationary periods under the Minimum Wage Act also does not apply to convenience-store sales workers and others engaged in simple labor.

Online commenters were divided after learning about the story. Those who criticized the store owner's attitude said, "This was a genuine emergency, but the owner crossed the line," "Deducting wages earned in a previous month is clearly illegal," and "This is grounds for reporting the owner to the labor authorities," condemning the owner's notice that the day's wages would be deducted.
Others expressed some understanding of the store owner's position. One online commenter wrote, "The owner must have been through a lot to react that way. We need to hear both sides," "If you miss work on the same day, you should at least have verified it with an emergency-room receipt," and "If you're a store owner who has dealt with part-time workers who habitually miss work with excuses, it's somewhat understandable that you'd react that way without asking questions."
[email protected] Sung Min-seo Reporter