Responses
I don't think a 12 year old would have the power to convince their Dad's worker to hurt them. Also, when they collected Yul they specifically said Yijung's Dad wanted to treat him to dinner but to get there he'd have to ride in the car. If Yijung had planned this why would they need to use that cover story? Also when Yijung calls Yul to get out the car you can hear someone trying to stop him from telling Yul. Yijung's parents definitely planned it.
I think Yijung was trying to get himself hurt again and HE was supposed to get in that car but that old man mistook Yul for Yiyung