>The 5D is smaller and cheaper than RED, but not that much.

The RED approaches $20,000-$30,000 all in, no? Compare this to <$3000 for the 5D.

You can use any normal canon/zeiss/sigma lenses on either system.

The Canon is something that "regular" people have; several of my friends have them. You can walk into a fry's and buy one. This is not true of the red.

They're in entirely different leagues.

Correct. A fully rigged RED will put you in the $50k range. The RED is 100% designed as a filmmaker's tool, it is as solid as a rock. You can't even properly plug a microphone into the 5K-M2. But at the end of the day, they are both similar tools that create amazing imagery. Ford or Chevy for you?

The millions that Canon likely paid them probably had something to do with it.

Or, possibly, like they said in the article, they're doing it because the 5D is more mobile.

It could also be due to an increased experience handling the Canon product line, lenses and bodies.

apart from rolling shutter issue, the image quality you get with a canon 5d mkii is much better than you get with camera they use for TV shows