I don't really remember what I thought at the time, but I don't think she really wants the reader to believe that. It's again one of those matters of "no, you can't possibly do that without undermining yourself horribly", on par with the "no, Snape cannot be evil".

We have a long list now of reminiscences and references to book one in this book, no doubt all intentional. Griphook himself also appeared in that book, as was mentioned earlier.

Bill's comment about how it would be less dangerous to break into Gringotts than to renege on a promise to a goblin is great. I do wonder how he'd have reacted if Harry had answered "what if I do both at the same time?"

And while we're on fitting comments, Aberforth's scathing comments about their suitability of Albus' big quest seem somewhat like an apologia to me, the classic trick of having a character inside the book point out weaknesses in the plot so as to undermine critics who wanted to point them out themselves. But since it does make sense in context, it's not particularly bothersome.