Historical precedence is very important.
The idea that a 13 Win coach would actually take a demotion (unless he fails miserably in the Playoffs) is kind of silly and it probably hasn't happened and probably never will. Especially a guy that is under contract and the person replacing him would be an uproven assistant.
Yes, Wade Phillips said he never thought he would get another chance again. That has nothing to do with whether he would take a demotion or how long he will coach. He was just expressing his opinion that since he didn't do much at his other stops, he didn't think the opportunity would present itself again.
If anything, Wade Phillips' words should be more of an indication that he is going to ride this latest stop for all it is worth because he knows Head Coaching jobs are not that easy to obtain.
As far as Jason Garrett, no use re-inventing the wheel, so see InmanRoshi's post, which I agree completely.
The guy has us prime and prepped for a Super Bowl run and folks already have his pink slip, typeed up, signed, enveloped, stamped and ready to deliver.
Wow