After the timeline posted by MarkM, I don’t see this specific piece of information as all that critical. This isn’t a short story or a mystery in which we expect every moment to be shown to us. The general tendencies of Dale’s character and Shane’s behavior are sufficient in my view to make this plausible without a specific pinpoint. Shane and Dale have interacted enough for Dale’s suspicion to have been triggered. That’s good enough for me.
I disagree, this sub-plot is Dale solving a mystery, and his deduction is central to developing a potential schism. You can’t just have a character appear to pull this shit from the ether. That you’re cool with lazy writing doesn’t somehow make it no longer lazy. What’s most annoying is the suggestion that asking the writers actually provide a foundation for a character’s conclusions is somehow over-the-top rules-lawyering. If the “general tendencies of Dale’s character and Shane’s behavior are sufficient . . to make this plausible without a specific pinpoint” then why bother with any explanation? My guess is that most discerning viewers aren’t as easy going as you.
It’s not really presented as a mystery, though. He’s suspicious from the start and when confronted, Shane all but admits it. What you’re proposing that the story do is change the nature and character of the narrative from a drama about a guy like Dale and a guy like Shane into a police procedural. It’s only a subplot, and its one in which the audience knows what actually happened from the beginning.
You keep throwing up the word “lazy writing” but that’s conclusory. This Dale situation never actually takes me out of the drama or the plot. It fits the narrative and the characters as established just fine.
The story isn’t about how and why Dale figures out what happened to Otis. It’s about Shane’s character and his relationship with the rest of the group and how Rick and the others choose to deal with it when they find out what Shane did.
They may be lazy writers, but I’m loving the way they have made Shane into such an ambiguous character. He has done a whole bunch of wrong things (usually for good reasons), but seeing him sitting in the car with Rick last episode, after getting a few hard truths explained to him was a marvel (both for the acting and the writing).
Again, I disagree. First Shane doesn’t admit anything to Dale. That he doesn’t deny Dale’s accusations appears to have more to do with his refusal to “answer” to Dale for anything. Second, a part of this story is about how Dale figures out what happended to Otis, and it doesn’t take much effort to make this work. They even appeared to make a run at it (with the two guns coming back). They just failed. I’m glad it doesn’t take you out of the drama. It does me. Those are our personal responses and so there’s nothing to argue about. The argument I have is with those who mainatin that the writers did lay a complete foundation for Dale’s revelation. They did not. They fail to establish a critical premise. To this point, we still can’t get a consensus for how Dale knew Otis had Rick’s gun.
*the caveat to all of this is that I could have missed something. To this point, that does not appear to be the case .
I’m not sure why you guys think hammering away at this point is still productive. 
To be honest it’s partly because I truly hope I have missed something and someone is going to come along any minute now and show me the scene where Rick tells Dale he loaned Otis his gun. It’s also partly because I don’t like being called stupid. Mostly, it’s because this show has so disappointed me after such an exceptional season one that I’m filled with the rage of jilted lover.
Well, you’re obviously not stupid. You might be a bit obsessive…
I’ll take that.
A key point being missed between “Dale tells Lori” and “Lori tells Rick” is that Lori talked to Shane, threw Dale’s suspicions in his face, and he admitted that he did it for Carl’s sake.
Dale never went all Phoenix Wright on Shane. He always cased his accusations as suspicions. The point was never that “He didn’t have all the evidence, so logically Shane didn’t do it.” The entire run of the series has been that the world works differently now and killing a man to save a kid is too far, but accusing someone of doing that without direct evidence isn’t.
The only part of it I could say didn’t pass the smell test was Dale saying Shane shot Otis. It was an alright supposition (after all, there were lots of guns involved), but it was weird, psychic wording.
Aside from that, Dale’s suspicions, and Shane’s arrogance about them, all follow a logical thread.
And I disagree with you. I think enough explanation was given, that it is perfectly logical, and don’t need to have every last detail explained to me. Where you see lazy writing, I see sufficient writing.
I’m not going to claim it is great writing, nothing on this show has been great writing. And there is plenty of crappy writing to point at. I just don’t agree that this particular point is an example of it.
Also, it occurs to me now. If Lori really wanted to make sure that Rick did something about Shane why didn’t she just tell him, truthfully, that Shane had tried to rape her at the CDC.
I’m still surprised (given the relatively short period it has been since then) at how quickly that has apparently become a non-event for her. But I guess that heals faster than bullets to the chest.
It also occured to me before writing in post 67
Maybe you should stop watching the show, if it causes you this much anguish. 
I was able to follow markm’s timeline just fine as it was happening on the show. I don’t think the writers need to spoonfeed us. I’d rather they leave a few things for us to deduce than to insult our intelligence by meticulously spelling out the obvious.
Throw in some tits and you’d be in Spartacus territory.
That’s right. On reflection, I am not bothered by Lori’s role in the revelation after her conversation with Shane, so Rick’s “I know what really happened” comment is not problematic. It’s the way Dale figured it out that bothers me. If you’re going to use the guns as the thing that tipped Dale off then you’ve got to commit to it. Make it logical. This requires Dale knowing that Otis had Rick’s gun. They didn’t do this. They half-assed it.
I am not asking to be spoonfed or to have my intellegnece insulted. This is a critical fact that cannot be reliably deduced from the information given. The best we can do is guess–this is why we still can’t agree on how Dale knew Otis had Rick’s gun.* You should not have to guess a critical fact.
*I-might-have-missed-something caveat
and I’d be watching for a completely different reason
markm’s timeline is how I interpreted the events and it was pretty clear to me. Dale’s character had suspicions and a lot was communicated in the looks during the eulogy.
Meh. Some people are very intuitive. Dale had observed enough of Shane’s erratic behavior to realize that Shane was capable, and on the brink of, making a bad decision, which led to confiscating the guns, which led to the confrontation in the woods. It’s not a court of law where concrete evidence is needed to make an accusation.
For an example fo how it’s done consider the Godfather II [BEWARE: unboxed spoliers of this 40-year-old movie ahead]. Michael has Fredo killed because Fredo conspired with Hyman Roth to have Michael killed. How does Michael know Fredo betrayed him? Michael already supected Roth but thought there had to be someone on the inside. When Fredo is introduced to Roth’s second Johnny Ola in front of Michael, he awkwardly acts like they never met. Later at the brothel, a drunk Fredo let’s slip that Ola introduced him to the place. So Fredo did know Ola (and Roth). The chain is complete. That’s not spoonfeeding, it’s good story telling. Btu what if Fredo never mentioned Ola at the brothel. We might conclude that Michael was suspicious of Fredo’s familairty with a Havanna brothel, but that seems like a stretch. Michael has to connect Fredo to Ola. In the case of TWD, Dale has to connect Rick’s gun to Otis.
I guess I could live with the Dale-is-just-intuitive argument if they hadn’t tried to make it about the guns. If it’s about the guns then we need to know how Dale knew Otis had Rick’s gun. We should not be left to fill that in on or own.