Last night Obama administration officials told Congress that Hagel made the ultimate decision on the Bergdahl trade:

Secretary of Defense Chuck Hagel – not President Obama – executed the administration’s final call to proceed with the prisoner exchange of five ranking Taliban detainees for Sgt. Bowe Bergdahl, administration officials told Congress today in a classified briefing today.

“They indicated [it was] Secretary Hagel [who made the final call],” House Armed Services Chairman Buck McKeon, R-California, told reporters following the briefing Monday evening. “It was the president of the United States that came out [in the Rose Garden] with the Bergdahls and took all the credit and now that there’s been a little pushback he’s moving away from it and it’s Secretary Hagel?”