Well really he's been there once already.
I've deposed a lot of people. One theme that occurs frequently is that when the witness wants to create the perception that he had nothing to do with a particular action, he will feign more ignorance of the event than is reasonable.
Cooper did that here. He acted like he had only minimal knowledge of where his wife's body was found, and said things like "the report" said as if there were any reason to question it.
Yet if he had not committed the murder, his interest in the location of the body would have been intense for at least two reasons (discounting that he might actually have cared about Nancy and therefore have an interest in what happened to her which would have been the best reason): 1) the desire, like many people, to know who did this - in this case to his children's mother and his wife (wedding band on people yet he has no interest in the murder!) and the manner and location of the body disposal is relevant to that, and 2) if he felt like the finger were being pointed at him unfairly, the desire to know the basic facts of the case as close as possible to right the injustice and defend himself.
The feigned ignorance is superficial. It says, "I know nothing of the murder so I cannot give you any details about it which should tell you I had nothing to do with it." The deeper strategy would have been to show interest in the case, but that does have the risk of the attorney getting you to say something that maybe was not revealed in the press.
Anyway, I haven't watched the other videos, but this one follows a path taken many times before.
I recognize all the facts are not on the table yet, but that clip did him no good in my book.