There was another analogue (note I don't say "reference") between "Zhivago" and OUATITW that I noticed recently. The scene where Komarovsky finds Lara's mother poisoned and rushes through the house to write a letter and find help, etc., has a tracking shot following his movements through the house, etc., from the outside, even when he isn't visible (through the windows). I was watching that scene and I thought "now where have I seen this before?" and it finally dawned on me after about a minute that I was thinking of the aftermath of the shootout on Morton's train with Frank walking through the train. Now it wasn't exactly the same and again I doubt it was a direct reference (I'd bet that's a copied shot from an older film) but again, I found it interesting to see such a similar shot in the two movies.
It's not a reference. I highly doubt Leone made any references to Lean's films, except maybe Bridge on the River Kwai in GBU.
DYS probably took a great deal from LoA,
Well read some of DJ's posts above, he mentioned the scene with Arthur Kennedy and Omar Sharif as resembling the Juan/Sean discussion about "revolution". In terms of dialogue it isn't very similar, but the setting, etc., is certainly similar, though you can disagree. DYS borrows more thematically from LoA than in terms of literal scenes, the political aspects especially. The train attack scene put me in mind of the ones in LoA; though it isn't exactly the same, it's hard to think Leone wasn't thinking of Lean's film when he did that.
Can we agree that the possibility of LoA references in DYS isn't any more spurious than some of the purported "references" in OUATITW?
Maybe the term "reference" is what is hanging people up here. When I think of a director referencing the work of another, I imagine that he copies a set-up expecting some of his audience to recognize the original model. This is clearly what SL was about in OUATITW. In his other films, however, he may have only wanted to use shots that worked particularly well in other films for entirely utilitarian reasons, without regard to whether an audience would recognize a reference or not. It's possible SL may not even have wanted people to think of other films when watching his (again, excepting OUATITW). Still, you can't help noticing that sometimes SL seemed to have been inspired by shots in earlier works, perhaps even unconciously. The way in which the Bakunin scene in DYS mirrors the book-reading scene in LoA is striking. In both cases men are in camp, reclining, taking a respite from a military campaign. In both cases a book about politics is the occasion for a discussion about politics. I would not say that DYS is "referencing" LoA here, but I think it would have been unlikely for SL to do his scene the way he does had he not first seen Lean's.
I wonder if that coyote howl is a "stock" sound