>From what I read in a lot of places, 50 1.4G is slow in >focusing and softer than 1.8G (which is also faster focusing >and 60% cheaper). So while a particular D800 could have added >to the issue, I would say that you could have experienced >natural softness of the lens. Also, it is possible that you >had a bad copy, which happens.
Yes. I think your summation is correct. The fact that a pro photographer could not figure out the issue tells me that it is rather dicey dealing with the 50mm 1.4g. It certainly is a conundrum.