Well, Red John''s return is looking more and more slim.
Just saw an interview with Heller regarding the show being renewed. He reiterated Red John was McAllister and the characted is indeed NOT part of the show.
Heller stated:
"We know some folks think the Red John ending could have been different, but the show was not about him. We wanted to give Jane closure on his family's murder so he can focus on being a mentalist. That is what the show is about"