When the villain, Young-Sook, kills off the father of Seo-Yeon, the latter screams in terror as she sees how he fades away from her life. Yet earlier, when Young-Sook kills the strawberry farmer Sung-Ho, who at the time was having lunch with the parents of Seo-Yeon, they would have been alarmed and cried out in surprise as well, yet that did not happen.
In 1999, Young-sook says she is 28 and was born in 1972. If she was born in 1972, she would be either 26 or 27 in 1999. That's because in Korean culture people usually add 1 year to their age.