There was nothing in that episode saying McAllister was definitely RJ, i hope Jane gets a call in a future episode which says "Hello Patrick" in that creepy ass voice. That was a shit end to a good story and i hope Heller is lying saying it is definitely over.
Twice we have been told that RJ is medium height (just under 6 foot), medium build, not soft but not muscular(around 150-170 pounds)
Bret Stiles - too thin, not tall enough
Gale Bertram - too tall, too "well-built" for RJ
Brett Partridge - ideal height, possibly too thin but could be classed as medium build
Ray Haffner - a little too tall, perfect build
Bob Kirkland - a little short, good build
Tom McAllister - bit tall, good build, perhaps too "well-built"
Reede Smith - too tall, too big
From this we can definitely eliminate Smith and Stiles
Now age, RJ is middle aged
Partridge is too young, Bertram is too old, as is the Sheriff
Now we are left with Kirkland and Haffner
Kirkland has been shown to us as an obvious choice for RJ, but way too obvious. My bet is Kirkland has his own personal reasons for why he wants RJ dead. The hospital scene where he asked one of RJ's followers if he recognizes him is puzzling and will perhaps be revealed to us later on in the season. Kirkland has a weird voice which is what was described by the little girl at the cemetery , i could definitely see him putting on the RJ voice from the phone calls.
Haffner is the right height and weight for RJ , but i can not see him putting on the weird voice. The visualize part makes me suspect him alot, but this also seems too obvious. Bruno Heller says he knew who RJ was right from the start of season 1, and the only person who has been with the series that long is Partridge. I personally do not think he is RJ as his actor has confirmed Season 6 Episode 1 was his last appearance in the series.
With all the suspects pretty much ruled out, i think Gale Bertram is the strongest candidate. This is 100% reliant on the fact that Heller said he knew who RJ would be right from the start, and a Future Chief of the CBI is the only part i could see being set in stone as a future character.
As none of the clues point to one suspect
1) Heller has lied and he didn't know who RJ would be right from the start
2) The medium build and medium height clue is false, as none of the suspects really fit the description except i guess Kirkland.
3) RJ is not one of the 7 suspects
All of the clues will come together and i think everyone will be surprised when we reach the 8th episode of Season 6 and RJ is revealed, but for now, Heller has purposely made it so none of the clues can point to one character alone. All the clues point away from Stiles and Smith, so i am not sure about that. But my money is that either Haffner or Bertram is RJ.