He was just paying lip service.
Fact is, Capers has been a HC before, and hasn't had much sucess. True, true, he led an expansion team to the NFCC game, and he only took expansion teams.
But I believe even he knows that his calling is DC. He spent a lot of time with "small" jobs, nobody would take a chance on him, before we took him as DC.
Capers can be a HoF DC if he stays in GB. At least be recognized as one of the best DCs ever. If he goes Head Coaching, probably he won't be recognized as a great HC.
Contrary to the up-and-coming coordinators, he's old, and he's had his chances.
Some guys are made to be coordinators, or position coaches. I think Capers is one of them.