Hagel is he a scapegoat for the Obama administration?

This was the best I could find.

On November 24, 2014, The New York Times reported that Hagel would be resigning from his position as Secretary of Defense under pressure from the Obama administration. Later that day, President Obama announced Hagel's resignation and thanked him for his service. Hagel said in a statement, "You should know I did not make this decision lightly. But after much discussion, the President and I agreed that now was the right time for new leadership here at the Pentagon."

Hagel did not deny rumors that Obama asked for his resignation, but he explicitly contends that it was a "mutual decision" between him and President Obama. Senator John McCain offered his own insight: Hagel was frustrated with the White House decision-making process, national security policy, and "excessive micromanagement" within the White House. In December 2015, during an interview with Foreign Policy, Hagel stated he was "backstabbed" and accused administration officials of making anonymous comments after his resignation in an effort to destroy his reputation.