Smiling faintly as he walked out of court, former IMF chief Dominique Strauss-Kahn was released from house arrest Friday after prosecutors acknowledged serious questions about the credibility of the hotel maid who accused him of sexual assault.

The charges against him stand — for now, at least. But weeks after saying it had a strong case that was only getting stronger, the district attorney’s office was on the defensive. So was the housekeeper’s lawyer, who continued to insist that Strauss-Kahn had violently abused the woman.