Okay, I'm going to call BS, for the most part.
First, I think it is legitimate to capture stills from a video stream. Of course, if you want to do it right, shoot in raw, and that means use a RED camera, not the "c". They mentioned this in the video and hoped for the next generation, when RED is already doing it.
Second, and they mentioned this as well, stills settings are nearly always very different than video settings for the same scene. One might want 1/500th for stills (for reducing motion blur in the final frame) and 1/48th for video (for preserving motion blur to make the video look smooth). This means it's nearly never possible to shoot video and stills at the same time with the intention of using both as final output. You are going to have to pick one or the other in advance most of the time. Again, though they mentioned this, they glossed over it.
Third, if you need flash for your images, video mode is not much help. Flash is often an incredibly valuable tool for controlling scene contrast, and we stills shooters often don't really realize just how powerful our little on-camera flashes are. If you want to replace a 580, you might need a 20kW video light, which comes on a truck. So this stuff is really only for conditions where natural light is acceptable without modification. Of course, there are many times like that, but not all by a long shot.
Fourth, capturing 24 frames per second and then picking your frame often does the exact opposite of what is mentioned in the video - it misses the key moment rather than allowing you to find it in the video stream. Not always, but sometimes. In many cases, I can time my shutter release to within about 2ms for doing things like capturing a batter hitting a ball, a pitcher releasing a ball, etc. For 2ms accuracy, you need 500fps, not 24fps. Even if I'm only accurate to 5ms (I can nail that most of the time) you'd still need 200fps. So, in many cases, "spray and pray", even at ordinary video speeds - or even at RED's maximum of 120fps - is not sufficient to capture the moment unless your "spray" is at very, very high frame rates that neither the "c" nor any of the RED cameras can manage.
I want to reiterate that there are times when this approach can be useful, but it's no panacea as they try desperately to imply in the video.
Very well said.
I don't see where in order to "do it right" you must shoot in raw. However you capture a great image, that's how you capture it. Film negatives, slide film, 4x6, 110 film, FF digital RAW, JPG. It doesn't matter. It's the shot you get, not what medium/media you capture it on. Now, would I vastly prefer RAW of some kind to JPG? You betcha! Although for RAW video, the storage requirements balloon a LOT more. One thing to keep in mind.
As has been mentioned, just because you are capturing at 24/25fps, doesn't mean your shutter
is at 1/48 or 1/50. For smooth video you generally would want it closer to that, but as is mentioned in the video, 1/100 and 1/200 can still make reasonable video, and still be good for most stills. Not all of course, I fully submit, but many situations will still be able to be captured perfectly well at those shutter speeds.
The bit about lighting is on point, although you aren't always able to use them. But, as per the article/video, the 1DC has good, usable quality even at extremely high ISO levels. Alleviates some of the lighting needs, but certainly not in every case. For a studio, it might just be back to the good old days* of "hot" lights (* I'm not so old that I ever shot with them).
I'll submit that 24/25fps does take some of the control of exactly when the capture starts, but even so for many (not all) needs it should be more than sufficient. The 1DX can only capture at 12 fps, which is fully half of what the 1DC captures in 4K for video. I agree, when you hit "go" it likely takes a bit more of time to actually start recording than the 1DX may take to begin snapping frames, but if you can anticipate the shutter lack of hitting the shutter button, then you can adapt and anticipate the lag between capture starts which will let you get your shutter pretty close to when you need it, and crank the shutter speed up (decreasing video smoothness, but sharpening the image for stills) while still giving you double the available frames to choose from.
Last, I completely agree that as it exists at this moment with the 1DC, it's not useful everywhere, and I don't think the video really tries to imply that. Instead, it shows a different way to start thinking about capturing individual images. But that, in the opinion of those particular photographer/cinematographers, is good enough for many use-cases now, and floors them as to the quality they can get and that they already are working with mixed-media and this will only increase the opportunities that they have.