From the differing ways we treated the same two hypotheses just now I think we're disagreeing on how fine a distinction we accept between two hypotheses before we say that they're significantly different. From my perspective, apparating into the room and walking in under the cloak are functionally the same. In both cases, the purpose of leaving a charm off is to enable Q and H to walk out of the door as if they never left, and it's that which I'd say is a valid deduction. Within all the hypotheses which fit that pattern, some seem more likely than others, but perhaps none are more than plausible.