I have a 5d & 7d and grade it on Apple color and I don't think i could ever stretch my images like this.
Yes you can. Sure you may get some macroblocking if you use just one channel but proper color correction tools can work wonders. You could easily stretch quite a lot of 8-bit cameras that much and even way further. Just take a look at how Stu color corrects some 5d stuff on an older version of Colorista. Colorista II also works considerably better on DSLR material than Apples dated Color.
http://www.redgiantsoftware.com/videos/redgianttv/item/23/
Pushing colors here and there isn't the tricky part. Where 8-bit compressed cameras tend to really break apart is making masks from color channels etc. It's more about knowing what you are doing (knowing the tools and what to do) than the camera.


