Now, here's what has been bothering me lately: it turns out Snape was the eavesdropper who sent Voldemort to Harry's parents. However, in Goblet of Fire, Dumbledore testifies that Snape returned to the good side before Voldemort's downfall and turned spy at great personal risk.
In Half Blood Prince, on the other hand, Dumbledore suggests (I think pretty much states) that Snape returned to the good based on his terrible remorse after Voldemort killed Harry's parents. Since his failed attempt to kill Harry at the same time was Voldemort's downfall, and earlier Dumbledore said Snape came back prior to that downfall, isn't this inconsistent?
In other words, how can Snape have returned to the side of good based on his remorse at causing the death of Harry's parents (as stated in Half Blood Prince), and yet have returned to the good side prior to that occurrence (from the Pensieve scene in Goblet of Fire)?
Sorry this post isn't making much sense.
No, the timing as written is definitely off. I have to think that either Snape returned after finding out that the Potters were the target, but before their deaths (prophecy comes before Harry's birth, they aren't killed for another fifteen months) or that Dumbledore is allowing Harry to believe that remorse over the Potters is why Snape returned, while the truth is something else. I would go with Door #2, because it seems to me Snape must have had a better reason, and done something more than we know, to return and to have D trust him so implicitly.
But that's a good catch, it's definitely written oddly. Maybe she wants to draw attention to how illogical that train of thought is...