Someone else may have a better recollection of the details, but I believe Callahan was a fall-back option. I thought Pederson wanted to hire Dave Wannstadt (not that he would have been any better), because Wannstadt assumed he was about to be fired by the Dolphins. Wannstadt was retained by the Dolphins for one more year, so Pederson was left scrambling. Callahan, just a year removed from the Super Bowl was then canned by the Raiders. Pederson and Callahan were equally desperate. Thus, we had a marriage made in the pits of hell.