Actually, he had seen Deng Yu fiddle with that group photo before, and when he got up today, he found that the torn painting by Big Bear had also disappeared. Moreover, when the first hint sounded last night, he had indeed seen a man's silhouette return to the right corridor, but he didn't see which room he went to.
So, even though he didn't know how the fake painting appeared, he intuitively believed that the two missing people and the two vanished paintings were related. That's why he had encouraged Li Weiran to take the sketch, only to find, to his surprise, that Li Weiran didn't fall for it!
He hadn't cleared the game and couldn't leave the copy; if he couldn't produce some real evidence, he would only die there!
