Could be, but surely an airline captain with more than a half hour's airtime has seen a lenticular cloud before. We glider pilots wait in constant drool for "lennies". They mean atmospheric wave and that means high altitude fun!
FWIW, they're not all that rare in my area at certain times of the year, mostly winter and spring. In fact, they're common in March and April in SE Tennessee....
Lenticular clouds aren’t rare, but getting one thin enough, and at the right angle for solar iridescence, probably is. I’ve seen lenticular clouds many hundreds of times, but a uniform color iridescence in a single cloud only twice in my life (and neither was even a lenticular cloud). For comparison, I have seen the green flash twice, and sundogs probably hundreds of times. I’m in my 40s, and I not only tend to notice such things, I often look for them.
This SEL pilot always steers clear as I'm concerned about the 'ups' and 'downs' therein.
So, how do you determine where the 'up' and 'down' areas are based on the cloud orientation??Interesting home page, btw...