Okay, I watched Episode 1x02 again. Twice. That's the episode Sheriff McAllister is in.
Before I share my thoughts about him, I want to say something else.
You are a writer/screenwriter. You are writing a book or a TV show script. You have this big mystery plot. You do your best. You are spinning the spot. You are putting subtles clues along with some clever red herrings. You continue spinning the plot, more and more. Until you realize the plot has started to spin out of control. But you don't panic, because you are an experienced writer.
Let's say that in this particular TV show, for some reason, you have to present the audience with a list of suspects for the killings in your big mystery plot. You have a bunch of guys, who somewhat fit the profile of the killer and the clues you've planted. But you are not really sure, because you've lost control of the plot. You have to name seven suspects. And you decide to include one or two names, who will serve as an insurance policy, a bailout, just in case. Some obscure characters nobody knows anything about and whose stories you can safely implant in the main story and say "yeah, they were there the whole time, pulling the strings from behind the curtain". It's cheating but it happens, even with good writers.
I am starting to think this is exactly what has happened with The Mentalist and that's why people like Sheriff McAllister and FBI Agent Smith are on the list.
So, I watched Sheriff McAllister's episode.
1. Jane does not shake hands with him onscreen. We see the moment they meet, but we don't see the moment Jane leaves the town. So, yeah, they might have shaken hands when Jane was leaving. Possible, yet unsatisfactory.
2. Lorelei: "I only wonder why the two of you didn't become life-long friends ..."
Okay, maybe Lorelei meant "shook hands" figuratively, so point 1. is not a problem. But the "friends" part?
What we see from Sheriff McAllister is this: He greets the CBI team and shows them the body of the victim. Jane does his thing describing the circumstances around the murder. A minute later the Sheriff asks Lisbon "who is this guy?", learns Jane is a consultant and starts asking him stupid questions like "are you a clairvoyant, do you have psychic powers" while making funny faces. Janes explains he has no powers and the Sheriff asks him "so what is it you do exactly?" (with a funny/confused voice and a somewhat silly expression again). Then The Sheriff gets beaten by Jane at rock-paper-scissors six times in a row. He seems a little upset, but not much I think.
Then there is the Van Pelt incident when the Sheriff interferes with Jane's plan and is even considered a suspect for a moment. Jane is not there, they do not talk.
And that's it. The Sheriff spends the rest of the episode making more and more strange/funny/silly facial expressions.
There is nothing even remotely special or unusual in his short interactions with Jane. Not onscreen at least.
So, assuming the Sheriff is RJ, tell me this - how can Lorelei even think that Jane and the Sheriff might have become friends? Let alone wonder why they didn't. Life-long friends, yeah, right..
3. The only strange thing I saw was this: When Lisbon and Jane begin questioning that guy Hector, just before he starts talking it seems like he looks at the Sherrif. At least that's the impression we are left with. The Sheriff gives Hector a strange look and we hear a short spooky music. That's it. Probably doesn't mean anything.
4. Rosalind's description + age.
I am not sure if he fits Rosalind's description. He is about the same height as Jane (I think I saw 6 ft being posted here). He is neither muscular, nor soft. He might smell "of pine and nails and earth" as he is living in the country. We are shown his hands and I don't know if one could describe them as "rough" or "strong". He does not have a gentle voice. He is balding, or at least the actor is.
Age. The actor was born in 1955. If we assume this age for McAllister, this would make him 33 at the time of the Red Barn killings. I am 33 and nobody has called me "kid" for quite some time now.
5. "He is ma". I don't know. Someone here posted "He is marshal".
6. Visualize connection. None shown.
I don't know. He seems like a random guy to me. An insurance policy, as I said above. The only somewhat plausible theory I can think of is this: McAllister knows Jane has joined the CBI, so he decides to ask the CBI for help in a local murder case (which he might have orchestrated?) and see how Jane works. That would explain his strange behaviour with Van Pelt - he knows Van Pelt is with the CBI, he knows Jane is watching, he knows Jane will catch the real killer. So he decides to play a little game with Jane or to mock him or whatever.
