Here is a very good example. I have my headphones on right now and I can tell that it's clearly fake. The camera mic is very muffled, while the 'weird sound' is in stereo.
The video posted in first post, I listened to that with headphones too and I realised that the camera mic is in stereo. But now I'd say that the strange noise would distort one way or another while the wind is blowing into the mic. Also, the sound from mic and the strange noise have different phases. I don't know how to explain that but it just doesn't sound right.
Also, you should also notice the difference by listening to how wide the sound is. I'm not on headies at the moment, but with speakers I kinda noticed that the camera mic sounded pretty monoish with the wind noise etc. The 'strange sound' seemed to be in stereo and was almost clearly with alot better quality. Should've been muffled as the wind noise.