[Annnd he averts his eyes, fumbling with the chalk between his fingers, getting dust on his gloves.]

I cannot say for certain —[well, he could now]— but I have my guesses. I... I have an affliction that is said to taint the aura of the affected, among other things. I believe this makes me imperceptible to them in some way, as when I have neared them before, they paid me no heed. That, or perhaps they thought me not worth the effort.

[But given how mindless they are, he doubts that. At least all of what he says is technically true, even if he leaves out a vital part toward the end. The twice-cursed are said to have an aural taint, and he has been largely ignored by shamblers when faced with them in his work. He finds himself as reluctant to talk about his current status as one of them as he was of his curse when he was alive; however, given their current undertaking and the fact Qubit might be putting himself in danger because of it... well, even he realizes that full disclosure might be best.

Or partial disclosure, in this case. Selective disclosure.]