Suppose a student applies to a few good graduate programmes, but for some reasons, gains an admit in one great school and rejects in a couple of equally good ones. How necessary is it for the student to be truthful about his rejects? There are a couple of circumstances that arise here:
The student is invited to an interview at a school, where he is asked about his applications and decisions. Is it okay to lie that the results are pending? Or that he has been offered admits at a couple of places? It is likely that the student will face a dilemma if he feels the other decisions may affect this one as well.
Is it vital to be truthful at the graduate school you have joined? Is there any mutual communication between administrative sections of all top colleges, which may leave bluffing in bad taste?
One goes to graduate school to work in a field or with a certain researcher. That person, accordingly should have specific enough goals before applying that tweaking a scattershot approach shouldn't apply. In the extreme, you are trying to get into only one place and so the focus is more on developing a relationship with the "target" there.
That said, at least I have found my self in similar situations. As to bluffing. I think the best advice, if you feel the admissions officers are plumbing for advice is to say that you haven't found out yet. The advantage to bluffing is that it makes you look better inasmuch as one school will want another school's candidates.