Interesting side note to that abortion of an episode last night. It turns out PJ actually is Red John after all :) 

TV Guide Magazine: Any chance of a Jane-Lisbon romance? A lot of fans are dying to see that happen!
Baker: You will see that he really misses Lisbon and is a sad, floundering shadow of a man. He's afraid and just going around and around in circles. He's completely lost his mojo and he's asking himself, "Is this what you want to be? Is this the way you see the rest of your life?" He's offered a chance to go back to work for the F.B.I. and declines because he's trying to move on from that life. The episode has an interesting kind of noir-ish feel to it. Jane had been filled with this deep desire for revenge, which is generated out of self-loathing, right? Take that revenge out of the equation and he's just this guy who is empty. But the episode is also really romantic in a way, because you see how much Jane longs for companionship. You want to know something I've never talked about?TV Guide Magazine: Hell, yeah!
Baker: All those times we heard the voice of Red John? That was me.TV Guide Magazine: Seriously?
Baker: Yes! In the Season 2 finale, when Jane was captured and Red John did that "Tyger, Tyger" thing with the mask on? That was me. I played both characters in that scene.TV Guide Magazine: Wow. That's especially trippy considering there was a major theory going around that Jane was Red John. So in a way that turned out to be true!
Baker: That was the reason I did that. There was a point where Bruno was saying, "We don't know who we're going to cast to play [the masked Red John]." I said, "Don't cast anyone! I'll do it." Bruno was, like, "I love it! I love it!" So I put on a mask and did that funny, wispy little voice. And for seasons after, whenever Red John spoke, I had to go record the voice.

http://www.tvguide.com/News/Mentalist-Simon-Baker-Red-John-1073837.aspx