Maybe the character that JK was referring to hasn't even died yet. I mean, putting myself in her place, she's up to her eyeballs in book 7 at the moment, so maybe she killed a character at the start of book 7 but managed to bring them back. Trying to see it from her perspective, if she had always planned on killing off that one, then suddenly had a change of heart, she might toss us that comment and have some personal satisfaction in letting us fret it.

One more thing. I agree that Harry lost out on very important skills by not learning Occlumency and Legillimency, but I don't think he's going to learn them at all. DD would've been his best chance at honing these skills to even an amateur level, but who else is there to teach him, now? I don't believe that Harry will have time for learning any more major magic. His protective power (from the Dursley's house) will be ending, on or around his birthday. JK hasn't said how this will happen, if it fades or stops all at once. But, the time line of the story leaves off at the end of term, June. So, Harry has, roughly, a month to get to the Dursley's house, then, back to the Burrow for Bill and Fleur's wedding, then he said he'd visit Godric's Hollow, plus he's still got to find those Horcruxes. That seems like an awful lot to accomplish, and I'm sure, even with that much, JK has to be tying up loose ends along the way, answering the questions she's led us to ask for the past six books. It seems like JK would need to write at least four more books just to end this properly ( though I wish she would write a dozen more!).