I don't know. I don't think there's anything more to JKR's words and actions than a sincere belief they are hers and not Steve's - she's essentially trying to keep RDR from publishing her words again and putting someone else's name on it. I was surprised to read that she was close to tears, but I suppose it's not really a stretch - maybe when the question was asked she genuinely looked at the hardest times of her life (before her books were published) and it hit her at once what Harry and her work and everything that led to her success meant?

Who knows, though? Maybe everything will come out after the trial - or, more likely, nothing will.