We know that parts of "Windhorse" were secretly filmed in Tibet. One has to wonder why. Most of the film consists of "Tibet" duplicated in some other country; since nothing of documentary interest happens in the real Tibetan scenes, these might well have been duplicated too - especially since the Tibetan footage is blurrier than, and clashes with, the non-Tibetan footage. (It's obvious that it was furtively shot with a concealed camera.) The sheer pointlessness of incorporating real Tibetan footage, and the sense we have that it was risky to shoot and riskier still to smuggle out of the country, gives this footage an eerie quality - like those Russian photographs of the surface of Venus. But it's not an eeriness that adds anything to the film.
I'm not able to check this, but grant for the sake of argument that "Windhorse" is (a) based on actual events, and (b) represents those actual events as accurately as was in the film-makers' power to represent them. Well and good. All the same it's a work of fiction, and fiction requires something more than fidelity to the real world and worthy motives in order to succeed. "Windhorse" has little story, flatly and poorly presented ... indeed, I needn't go on, since nobody could even mistake this film for a good work of fiction; it's so lacklustre, in fact, that the only danger is that someone will mistake it for a documentary.
Yes, the Chinese occupation of Tibet was and is unjustified. I felt as if I we were being asked to sit through something - not at all painful, but terribly earnest and dull - as penance for living in a world in which such a thing was allowed to happen. I would have preferred a documentary. A good one of those would have tried harder to be informative. It would have told me what it wanted me to think, or what it wanted me to do, and then given me reasons why I should think so or do so.