Well we weren't told everyone is supposed to be locked in their rooms. Just like there is a chance he was doing something shady to hurt them all, he could be sneaking around to avoid an actual spy in their midst that he is trying to give wrong clues to or misinform without trying to get caught by anyone else. If anything, Max the tiger could be a spy. He got all worked up when things got complicated with the MC joining in and doing a new part in their schemes. He would have no time to warn the people he is working for, which is why he is (the only one) freaking out about a new recruit.
Again, I could be all wrong. IK not all story writers try to make things hard for their readers, and would prefer to highlight who the good and bad are. Benjie sneaking around at night as a major clue that: because he isn't acting like one of them, it means he is not one of them and is a traitor... or something. / I just don't like easy clues. Makes me feel like I am reading a children's book or the day dreamings and fantasies of somebody else who is sharing it, just with some contexts here and there so it can make sense to readers. I like a little more purpose and intent whenever a character does or says something, rather than just judge them on the first impression because of their position or mood . Didn't grow up on Scooby Doo for nothing ya know?