The point is that the Cheng et al results and paper were shown to Google and apparently okayed by Google points of contact. After this, complaining that Cheng et al didn't ask someone outside Google makes little sense. These far fetched excuses and emotional wording by Jeff Dean leave a big cloud over the Nature work. If he is confident everything is fine, he would not bother.

To clarify "you'd expect" - if Jeff Dean is correct, he'd deny problems and if he's wrong he'd deny problems. So, his response carries little information. Rationally, this should be done by someone else with a track record in chip implementation.