Comey gave her a get out of jail free card.
Comey gave her a temporary reprieve. The AG can lift that reprieve whenever he wants.
Personally, if they were to even hint at something like, opening up an investigation, they’d put out some life threatening illness that she’s been coping with, for years and is unable to stand trial due to the stress. Which, then shows that they were lying the whole time about her fitness for office. I think, if it were to ever come to it, she’s screwed either way.