...I've never so much as heard the implication that Voldemort was actively sabotaging the Defense position so much as he cursed it once, and it is the curse that is continuing to do its work. Such speculation doesn't appear to make sense to me now that I have heard it.

Linking the burnt chicken to the burnt husk of Voldemort's supposed body, however...is not something that I've considered, and it actually makes some sense, though I do not say that with a high degree of certainty. Though, why wouldn't he have spoken up by now?