For some people, those with super photography skills, this may not be that difficult. For me, it is. To illustrate a few key points, I'm going to show some examples from a self-portrait shoot I did a couple years ago.
Oops, cut my head off. Reposition the tripod and let's try again.
This one's not too bad, but the lighting is a bit wonky. Try again.
The lighting is better, not perfect but can be fixed in Photoshop. My head's a little cut off, but not too much. Still, let's give it another shot.
Dang, this is SO not in focus. And what's with the wonky head tilt? Try again.
Sigh. Lighting's good, it's in focus, nothing's cut off, but dude why do I look so stern?
And so on and so forth.
Now any time you take a photo of someone, you have to concern yourself with these issues ... composition, lighting, focus, facial expression, body position, etc. But when the subject you're photographing is yourself, it becomes more complicated. Because when you look through the viewfinder, your subject (you) is not there (I know, DUH!). There are some tricks you can use, such as placing an object (a stuffed animal works well) or another person as a "stand-in" for you. You compose the shot, focus on the stand-in, set the timer and then take their place.
But still, it usually requires more tries to get a good self-portrait than it does to take a portrait of another. On the day noted above, I took upwards of 40 shots, just to get one usable one.
You might ask, "but what about action shots?" Can one take a series of action photos without using another photographer? Well yes, they can. Certain remotes, use of auto exposure bracketing and even a computer rig-up can make this possible. Another option would be to shoot video, then extract images from that. That's a lot more trouble than I'd be willing to go to, but it can be done.
So my whole point here is that we simply can't assume because a photo looks "too good" to have been taken by the subject, or "too difficult" for the subject to take, that it wasn't indeed taken by the subject. We don't know how many tries came before it, we don't know how skilled the photographer is at taking self-portraits, we don't know what equipment they have available to assist them. In fact, the photos that are at the heart of this controversy don't appear on their face to be any more questionable than any other self-portrait. It is the evidence outside the photos that shows they were not taken by the entrant.
All right Barb, but what does this all mean? Well, what I think it means is this. This contest really does have to rely heavily on an honor system. Many rule violations would be practically impossible to spot. I don't think CK needs to take on the burden of overturning every rock, stone and pebble to ensure compliance with their rules. I do think they need some sort of audit system to review winning entries, to look for irregularities that raise a red flag. Then contact those entrants and seek further information. It's not that difficult and it's not that onerous. Do 3 photos of a person performing the activities of a triathlon coupled with writing about a person training for triathlons appear suspicious? Sure they do. So call the entrant, ask if they are photos of her and ask whether she took them. Maybe she took photos of someone else and wrote about her own experience. You don't know unless you bother to find out. Do 2 apparently sequential photos of a person getting on a horse raise a red flag? Maybe, although as noted above, it is possible to take sequential timed photos. Still, if you're unsure, call the entrant and ask "Is this you? Did you take those photos?" Look at the supply lists and other documentation. Does anything stand out as not right? Check up on it. Legally they don't have to do this; ethically I think they should.
And then if a few rule violations still slip through the cracks, so be it.