I have some shot's digitized that were just that example (sky shot's). Their is not apparent split screen, frame for frame, on the stuff I have. Maybe you could try to confirm as well?

I have actually asked Nate Weaver, on another post about the split screen issues, but i felt uncomfortable about bringing it up in the thread I was in... so I will ask it here since you seem to be talking about it...

Nate's music video is done and up on his page and it looks great... in my opinion the public and pros alike would probably not be able to tell the difference if it was shot in film or HD. I have a pretty good eye and I saw nothing that didn’t scream the film look in his end product.

I wanted to know if anyone on his set, or friends who know, have seen the lighting set up he used... My reason is that im shooting a film that is about 60% in dark situations (basement with 1 harsh light for lots of dark area and dramatic shadows) and much more including outside night shots. I want to get the deep dark blacks all over but have shadows and half face shots of actors in harsh light. Problem is, from what i hear this is a perfect way to get the "split screen" problem! So what to do? Stretch blacks in camera... crank lights all the way up and then add lots of contrast and bring down the brightness in post... what should I do?? Please help :-)

Nate can give a more definitive answer, but I believe his key sources were a couple 2x4' 3200K KinoFlos.
He used a dimmer to get the flicker near the end.