Why Moo Won avoiding Nak won

Na moo knew very how deal with the physcopath . Too good acting by Na Moo ,Na won and Hyun . Last scene they had shown the camera as soon as Hyun left room .Did this camera will steal . He has only evidence to proof he is innocence though he hide the murder suspect so he will be punish for that then to if the camera lost then what will happen .Why Moo won avoid Nak won ? May because she is getting close to Na Moo.