“Wasn’t she let off the hook long before Sessions ever left the Senate?”
Yes; long before, IIRC.
It does appear to be a Yes and No situation. Another one of those “no evidence - no bias - no crime” we’re becoming quite familiar with today.
https://legalinsurrection.com/2017/09/doj-standing-by-decision-not-to-prosecute-lois-lerner/