An argument between a local resident from the US and an older Korean man escalated, leaving the latter with a cerebral haemorrhage, according to investigators in Muan, South Jeolla Province, Wednesday.
The 64-year-old victim, identified by his surname Choi, had demanded his neighbour leash his dog inside the common lift.
Following a squabble rife with miscommunication, the foreign national in his 40s pushed Choi from the lift.
Choi reportedly fractured his skull and suffered a cerebral haemorrhage. He was taken to a nearby hospital where he remains unconscious.
The case came to light after Choi's son looked up CCTV footage and discovered the cause of his father's sudden accident.
The man accused of assault reportedly told police the harm caused had been unintentional. He had only meant to shake away Choi as his co-habiting partner, who was also present at the scene with another unleashed dog, was ill.
Police have barred the man from leaving the country as they investigate.
Unleashed dogs have increasingly become a source of social concern.
In November 2016, a dog off its leash attacked a woman and left her in need of six weeks of hospital care. The owner of the dog was fined 4 million won ($3,550) for gross negligence.
Also, on Friday, four hunting breed dogs strong enough to overpower a wild boar attacked a couple in their 40s while off their leashes in Gochang, North Jeolla Province. The dog owner was booked without detention by police.