For asking if she’s a “flake,” but Bachmann has refused the apology. The Hill:

Rep. Michele Bachmann (R-Minn.) said she wasn’t accepting the apology of Fox anchor Chris Wallace, who asked her Sunday if she was a “flake.”
Bachmann rejected an apology from Wallace, who challenged whether the Tea Party-aligned congresswoman was serious in her bid for the Republican presidential nomination.
“I think that it’s insulting to insinuate that a candidate for president is less than serious,” Bachmann said in an interview on ABC when asked about Wallace’s apology, which he posted online.
“Those are the small issues,” Bachmann said when specifically pressed about whether she accepted the apology. “I’m focused on the big one.”