I finally got him to talk. Not much, but enough that it was a concerning offense. Here's how it went down. This is all paraphrased, by the way.
Me: What is this? [I gestured toward the doll sitting on the table near us.]
Him: A doll. Just a doll.
Me: Why are you afraid of it?
Him: It's a bad omen for it to have appeared.
Me: What does that mean?
Him: Bad things are going to happen. I'm sure of it.
Me: Okay... Then who left it?
Him: Dunno. [At this point he looked quite serious.] Could be anyone, really. No one who left it would remember ever being here, though.
Me: Why wouldn't they remember breaking in and leaving something like this?
Him: It's things like that that you don't remember. You know, I bet you've.... Well, in any case, I don't know why someone wouldn't remember it.
Me: ....you're not going to take it and sell it, are you?
Him: I don't think I should even so much as touch the thing.
Me: And you're not going to explain why my tattoo was in that Marble Hornets fake ghost bullshit, are you?
Him: I didn't see your tattoo in that. How can I explain what isn't there?
Me: Okay.....Then what---
Him: [He interrupted me here.] I think I'm gonna go home now. I've got an early day tomorrow. [He started walking toward the front door.]
Me: Alright. See ya. [I saw him out after this.]
It was after he left that I realized that I forgot to ask what he bet I did. Whatever, I'll ask when I see him next.