Guinan's vision was because she was picked up from one branch and set down in the other, and saw that she had an unexpected landscape around her as she went down the river, while everyone else just flowed down it naturally and so it's what they'd always expected to see. Not because it wasn't the original, but because it wasn't the one she came from.
Well, not exactly. That Guinan was the one from the Klingon-war timeline; she just had the ability to perceive that it was the result of a temporal disruption and that there was another, "better" timeline out there. As we learned in Generations, her time sense was the result of leaving a piece of herself behind in the Nexus. Thus, some aspect of her consciousness existed "outside of time" and could sense temporal anomalies or shifts.
Anyway, we've drifted off-topic, haven't we? This was supposed to be about tie-ins offering different versions of the same event. And there's kind of an example of that here -- Vendetta assumed that Guinan's time sense was an intrinsic ability of her species, since it hadn't yet been revealed that it was a result of her own Nexus experience.