What are you claiming?
1) a power output of 6.6 watts/g for 40 min does not necessarily reflect either a V02max of 100 ml/kg or an efficiency of > 27%; or
2) It does, but neither of these values is indicative of doping.
If 1), what V02max or efficiency values do you think would be consistent with that power output? If 2), can you name a single athlete in any sport with either a V02max value or an efficiency this high? If you can’t, wouldn’t you say that doping is the more likely explanation? That's what Ross is saying, and I don't see how anyone could disagree with that conclusion.
I see nothing in that quote that indicates Ross believes that power values should be the basis for a sanction. The test he proposes (though I really don’t see the point of it, unless he believes, as you do I think, that any efficiency value, no matter how high, could not result from doping) is simply “to clear his name”. That is exactly what Sky attempted to do by releasing some of Froome’s power values. No matter what those values had been, they could not have been the basis for a sanction.
You’re claiming that since a power output that high can’t be proven at a very high level of significance to be unattainable except by doping, we shouldn’t conclude that the rider is doping. But I could just as well turn it around and say since a power output that high can’t be proven at even a moderate level of significance to be possible without doping, we shouldn’t conclude that the rider isn’t doping.
You want to err on the side of caution. But since sanctioning the rider is not an issue here, there is no justification for doing this. All we're talking about is which is more likely, doping or not doping. If doping is more likely, then suspicion is completely warranted.