Many Canon Rumors trolls may experience great satisfaction from demonstrating that ~2 stop deficit in low ISO DR by shooting images with the lens cap on, then pushing those images 4-5 stops in post.
Many times in the DR debate, those bashing Canon sensors have been asked to provide examples of shots ruined by Canon's 'poor low ISO DR' that would have been saved by those extra two stops. Personally, I have almost no examples of that situation - in many scenes, the ~12 stops I get is sufficient, and when the scene DR is greater than 12 stops, it's almost always greater than 14 stops, too.
Dude, it's not just the extra DR but the rampant noise in the shadow details of Canon files. This all but makes the bottom stop or two useless.
To give you an example of a scene I tried (and failed) to capture with Canon equipment, I had a setting sun behind a building that I could see through the door on the east, down a corridor and out the open door on the west side. As you can imagine, the detail outside the building on the west side was brightly lit (direct/diffuse sunlight), the side of the building I was on was maybe in the 50% grey area and the interior of the building was quite dark. There was very limited ability to expose to the right due to the outdoor area being lit by the sun but at the same time, if I didn't push it then the interior was lost to noise from Canon's sensor.
So to mimic what has been said about the dynamic range of the 5D Mark II (and by extension at least that of the 5D Mark III) "usable DR of the camera is one or two stops lower than what is measured due to the inability to use the shadows."
So what. What I always find so interesting about these discussions is that at the end of the day, based on all the examples that people tend to put up (the photo you are referencing most likely no different) this superior "state of the art" sensor technology with all this extensive DR advantages has done very little to advance the state of "ART" with regard to photography. If it really produced the dramatic advances in Image Quality that the proponents always claim, it would have gained significant traction in the market place. If IQ were really a significant problem with Canon equipment as the Sony/Nikon proponents like to conclude, nobody would buy Canon product -- yet countless thousands of photographers have been able to use it with tremendous success despite this corner case limitation.
I think what really frustrates the Nikon/Sony fan-club is that despite what really is a significant difference in measurable performance between the system implementations chosen by the two manufacturers, it really is mostly a corner case issue and hasn't really proven to affect the bottom line enough to force Canon to address it.
The endless barrage of poorly executed example images just hasn't gained the traction they expected. The reaction to most of these (and there have been a boat load of them over the years) has been "yea... but why do I care". The best example of this is probably the oft quoted Fred Miranda review where the reviewer shot two pages of magnificent images in Yosemite and could not produce a shot where the DR of the camera was a limitation -- to do that he gad to shoot something way less compelling. Both sides seem to be reasonably satisfied with their choices. Do I wish I had the same low shadow noise that I could have with a Sony sensor probably yes, do I wish Canon would solve it -- probably yes. Has it ever gotten in my way, no not really.