I was there on Sunday and it either didn't happen at all or it was extremely weak. As far as I could tell, the waterfall in question is currently completely dry.

Also, it looked like either a telephoto lens or a pair of binoculars was needed to get a really good view (anything comparable to what you see in the video).

Very impressive! Wonder which other mountainous places have such ephemeral features. Was on Pfeiffer Beach in California one time and there were a couple of dozen photographers there all standing on one spot. Thought they were a local club or something but they were all there independently to capture the sun setting behind this particular rock arch. I guess over the course of the year the position of the sun on the horizon moves around slightly so it doesn't always hit the right spot.