The Dolphins management might be tanking, but their players and coaches aren't. They really didn't want to lose this game and they came to play. I think Rosen gave them a bit of a spark early.
But, yes, the Cowboys were guilty of some sleepwalking too. They weren't sharp in the first half and had to take halftime to rally and get it together.
Still, I'm going to credit the Dolphins a little. They had far less quit in them when they weren't being saddled with Fitzpatrick and were given a chance to try to win.