I think you're being generous.  I mean, I think she did actually know better; but, that she was deliberately attempting to deceive the public (with the aid of an uncritical media).

If she really wanted to inform the public accurately in plain language she could have said something like "the much higher prices we are seeing aren't going away; but the good news is that eventually, they will getting even higher slower."  The administration would have dumped her on the spot.