Alright, time for some concrete evidence. Here is a 5-frame bracketed sequence I took yesterday of a sunflower field at sunset
to be honest, you overpulled anyways compared to that D800 picture, and there's something "wrong" with that D800 one, especially the sunflower to the left of center - AND you're only seeing it as a very small image so you can't tell if / how there is any artifact happening as you blow it up either. and that sun doesn't look right on his shot either (unless that's a nuclear explosion that just went off)
point is, if you need 10EV of latitude such as this shot, it's always going to be tricky.
I would do the bracketting and a much finer level of merging the photos as your best bet (and with this guy's shot as well )
not to mention, something looks "false" about the entire thing anyways, it's too flat, there's no shadows - my mind looks at that and goes - what planet is this from where there's light bouncing back behind the sunset?
How about this one then ?
Look at all that wholesome DR