Another random headcanon: John forgetting which information was given to him by the eye and which he was just told. So he randomly drops information he shouldn’t know in casual conversations like
John: hey remember the guy you hated from your old place you used to work at, the express delivery place? I think his name was Tom?
Martin: yeah- wait. I never told you about Tom nor my previous workplace.
John: oh I guess that one was the eye. Well anyways apparently he got fired so he decided to set on fire the car of the ceo.
Martin: Hah, nice.