I have GMed games with lore checks a lot: mostly RM and 4e D&D, also some RQ, and it comes up a bit (in the form of EDU checks, mostly) in our Classic Traveller game.
The PCs encounter a ghost/haunting spirit of some kind; a lore check is made; it succeeds; it is now established that one of the PCs knows that the ghost/spirit is immune to Xs but vulnerable to Ys. All the PCs put their Xs away and pull their Ys out of their backpacks.
That is "going back in time" - or, more exactly, establishing some details about a prior moment of learning for a PC - which then changes the event that takes place in the present (ingame) moment, namely, the way the PCs are equipping themselves to tackle the threat that confronts them.
Upthread I quoted Gygax in relation to this very point, when he discusses the thief's Read Languages ability. This is exactly what that ability is: a successful check establishes that, in the past, the thief undertook an action of learning a foreign script which now changes what is taking place - ie the thief can, rather than can't, decipher the markings s/he has just encountered.