If we go back to season 6 episode 01. We see Partridge seemingly "slaughtered" by Red John. If Red John already knows Jane's list, surely killing one of the suspects would increase the chances of the other 6 suspects being Red John. In addition, why would Partridge say "Tyger Tyger" before dying? Maybe because he is Roy Tagliaferro. Jane describes Partridge as a showman: someone who wants to strike fear into his victims, which is shown by the intricate way he kills his victims. I think Partridge is Red John, but set the killing of Sophie up in advance before his death, to try and confuse Jane and put on the perfect show. However, we know Red John started killing a long time ago, probably before Partridge's time. Which leads me to believe, that someone else was the original Red John, such as Brett Styles? But in old age, he found he was no longer capable to carry out the killings and entrusted Partridge to continue his legacy. Furthermore, the person who hit Lisbon on the head was probably an accomplice of Partridge.
To conclude, Partridge is the present Red John however sacrificed himself, in order to confuse Jane and put on the best show possible.
Anyway this is just a hunch. Might not be correct but who knows.
