but that's the only one I had in the Library.

Why was it caught on video? Because they knew something was wrong. These things are monitored at a central office, and if one is acting weird, (like not tilting to change the drag profile) they are going to go have a look see.

Now, if this was at night, and there are a handful of techs checking it out, what do you think they'd do? Maybe shine some of those really bright lights at the vanes to see what they were doing. I wonder what that looked like from far away, high power spot lights reflecting off a giant spinning fan into a cloudy sky?

(how come all my posts lately are about wind?)