This interview with the writer of The Red Tattoo is very revealing:

http://www.tvguide.com/news/mentalist-red-john-visualize-ray-haffner-1072592.aspx

If you look at the responses, it seems quite clear that Haffner is not Red John, although the writers wanted the viewers to suspect that perhaps he is, or that he is working for him or the TT conspiracy. For example (emphasis added by me):

"So you have this effect of, either he's [Haffner] Red John, or is he like John the
Baptist, the one who sort of comes before Red John? Is this Red John or
is this just this tool of Red John that is showing up to sort of throw
Jane off? Who's the puppet master behind it? Is Bret Stiles doing all
this to sort of screw with Jane's head even more than he has in the
past?"

... Haffner tells Jane there's a "comeuppance" heading
his way and makes reference to the fact that he has friends in CBI. Can
this be seen as an allusion to the "Tiger Tiger" conspiracy that was
teased in last week's episode?

Mahoney: Yes,
I think that's exactly right. Ray Haffner is a guy who used to work in
CBI. He's a guy who has connections all through law enforcement. We're
giving the audience information that our team might not have yet. The
team takes this as, is this a Red John threat? Is this a Visualize
threat? But I think you're exactly right, and I think the audience
hopefully is going to pick that up. What Haffner's talking about is
there's chatter in the world of police. A lot of people have this sense
that there is a secret society out there. And there are rumors that Jane
has really pissed those people off, and that's a dangerous thing to
have done.

" ... It's important to remember that Ray Haffner has not had a particularly pleasant experience with Patrick Jane. [Laughs] And
while Ray Haffner really does have a genuine fondness for Teresa
Lisbon, Patrick Jane to him is just a nightmare. He's the guy who
screwed up Haffner's chances of sort of moving up in the CBI. To some
extent, I suspect [Jane is] part of Haffner's motivation for leaving
CBI. Jane is that guy who's just always one step ahead. For Haffner,
throughout this episode, he's very happy with the idea that there's a
case that Jane seems to be stumped by. Unfortunately for him, of course
that turns out not to be the case. But essentially when he's saying to
him, "You've got a comeuppance coming," he devoutly wishes that to be
true. And from the rumors he's heard, he's pretty confident that that's
going to happen."

*******  THIS IS COMPLETELY AT ODDS WITH RED JOHN. Is the writer here revealing that Haffner is not (can not be) Red John?

"Jane is going to sense clearly that there's the threat of Red John, and
then there's this other threat. Is this Red John, or is this an entirely
separate other thing? Are they connected? If they are connected, how?
Certainly we've heard Red John say "Tiger Tiger" to Jane personally. But
again, is that Red John just screwing with Jane? Is that giving him
clues that are helpful, because why would he do that? Or is it giving
him clues that are going to lead Jane into traps? I think that's one of
the things that Jane now has to figure out. He's putting together all
these clues that he's got, but which ones are the ones that he can
trust? What's the direction that he should be heading in, and where are
the traps that Red John is leaving for him?"