I 'll start by saying that theories about Patrick Jane are completely unfounded and ridiculous , Bruno Heller say several times that it was not and could not be PATRICK JANE !
Here is an interview with Bruno Heller who also said :
http://www.unificationfrance.com/?26927-Mentalist-La-liste-de-Jane-est
We also note that Bruno Heller confirms that THE suspect in the list of Jane .So what theories like all members of the list would be involved is wrong.

I also found an interview with Jack Plotnick (Actor Brett Patridge ) who says that we often see in Season 6 , or he dies in the first episode. So it would seem that he must return to the other episodes .....
http://www.tvequals.com/2013/09/23/exclusive-interview-the-mentalists-jack-plotnick-talks-playing-br....

My theory is that Brett Patridge is not dead and he is Red John . He would fake his death so that Patrick Jane can no longer accuse him.