If you let the clip load completely and then move the dot on the bottom of the frame back and forth quickly you can see that the rings (that are not circular like a lens flare would be) move exactly with the rest of the CLOUDS and not in relation to the position of the sun which movement is only minimal. That means the motion of the reddish objects is determined by the wind and not by the position of the sun, ergo: No lens flare but a physical object in the sky.

Aside from the fact that I've never seen a lens flare that looked like this, the rings are moving with the clouds. If it's fake, it's pretty darn good, in my admittedly non-expert opinion. There's now an option of viewing time lapse versions of the video and you can see that this isn't a lens flare.

By moving the the frames forward and backward, the ring shapes morph, as do the clouds. It would take a pretty sophisticated CGI tech to do that.

"There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy."

William Shakespeare --- Hamlet