That's deflecting his question. He specifically gave the context of just the Cowboys job, not the NFL as a whole. It's quite possible that what he actually said in that context was accurate -- he would only consider the Dallas job specifically. He was not going to get the Dallas job no matter his interest, I am very confident in that specific statement which is independent about speculating about UM's state of mind. It's perfectly fine to doubt that his comment there means anything now, but to apply the logic that if he wanted to coach in the NFL, then he would be doing so makes no sense as it's a completely irrelevant and frankly illogical counter to his specific question.
I would never try to read someone's mind, and of course what one person thinks at a given time can also change. So even his statement on that show - or any other prior statement over many years and examples - doesn't necessarily mean anything because people aren't static that way. How he feels right now - or even in one month, or six months - may change. I'm not speaking to anything specific about Texas and UM at all, but I'm very confident that in the past (which frankly may mean nothing now in regards to Texas), UM was at least open to the Cowboys job and the Cowboys were not open to him being their coach. (Jimmy Johnson/Jerry Jones history probably explains a lot of it in my mind)