Top screenshots: Before CGI switch. Below images are after CGI switch.
When seeing a video they point the camera down, so you "forget" the exact details of the wing. But when you put them next to each other, it's a dead giveaway.
I was looking at that video too and thinking it doesn't look or feel natural. It's a good trick and actually a good demo. I think the physics are kind of off in the final video though.
What's off about your screenshots? It looks pretty consistent to me, e.g. the shadows and the marking of the wings.
I definitely noticed that they didn't show the landing clearly. I expected him to fall if he had any kind of velocity going but it wasn't clear, and that seemed fishy.
1) Missing square element in real footage.
2) What bothers me more is that shadow properties are not consistent. In CGI it is more diffuse and changes properties like if the Sun is positioned 10m above.
It could be the camera being wonky, legitimate post-production work, auto gain adjustment, etc.
So, no, look at the equipment used, look at the mechanisms involved, and tell me that it is completely infeasible. Don't rely on analysis of some cheap Youtube video.
As for the black square, I'm willing to chalk that up to being under the fabric until its stretch taught.
EDIT: Black square is not under the wing--probably a patch if its real.
In this video: http://www.youtube.com/watch?v=Q0tKFOcHyrI#t=101s The switch happens in a moment of blur at 1:53.
Here's some damning evidence: http://i.imgur.com/LODDp.jpg
Top screenshots: Before CGI switch. Below images are after CGI switch.
When seeing a video they point the camera down, so you "forget" the exact details of the wing. But when you put them next to each other, it's a dead giveaway.