The problem for Clinton is that her explanation relies entirely on the willingness of the public to trust her on the assertion that she told the FBI exactly what she said publicly. First off, that's almost impossible to know. Second, we have some evidence that contradicts Clinton's claim. Most notably, the idea — which she reiterated Friday — that she never sent anything marked classified from her email account. Comey has testified before Congress that she did. Here's his exchange with Rep. Trey Gowdy (R-S.C.), who chaired the House Select Committee on Benghazi:

GOWDY: Secretary Clinton said there was nothing marked classified on her emails either sent or received. Was that true?
COMEY: That’s not true.
GOWDY: Secretary Clinton said, “I did not email any classified material to anyone on my email. There is no classified material.” Was that true?
COMEY: There was classified material emailed.