That is not reassuring. At all. Wash does his best to rein in his train of thought before it spirals into flat-out panic, but he's been paranoid for a very long time and had very good reason to be. It's hard not to freak out now that he knows the things that go bump in the night have been...watching him? Possibly?

"Let me guess: you think I'm all of the above." As far as he's concerned, the best defense is scathing sarcasm.