He took a new job in one day. He survived many firings with the Eagles, I doubt he will be lucky enough to do so with the Lions. Then that may be where the story ends.
From what I read he had more than one offer. I know he had another offer in CHI w Nagy as well. He may have taken this job for incentives, who knows. I don't believe he survived anything. I believe he was an asset that Lurie, Howie, and the other coaches wanted.