Okay so this is the first time I am posting a theory and it comes from the perspective of a PR specialist that does teasers, promo's and such for a living.

Just like Batman is the real person and Bruce Wayne is the mask, I believe RJ is the real personality with Patridge being the mask. So when this page and producers say "its not Patridge", its not the same thing as saying "its not this actor" they are just saying this character is not the killer, his alter ego is.

A play on words perhaps?

If Patridge the person and the actor playing him are truly really genuinely gone from the show, then its McAllister and if not, I'm dead sure its Patridge.