I don't know, really. My theory is that the harder you wind the film, the harder any foreign material gets ground into the film.

I have a film rewinding machine at work that can go so fast the reels make a "whizzing" sound as they cut through the air. I don't let people turn the speed up that fast because, when that baby gets going, you can damage a LOT of film, REALLY fast! When you slow the machine down, if you do accidentally damage film, the damage will be less severe and you will have a better chance to stop the film in time to prevent more damage.

Do I think that winding my camera is a 100% foolproof way to keep my photos from being damaged? No. But, I am pretty sure that damage is less likely to occur and, if it occurs, the damage will not be as severe.

Want to have some fun with static electricity?
One of the theaters I used to work at had a rubber mat on the floor by the film bench. We used to load up a reel full of old trailers (which were going to be thrown away) and get it up to full speed then, while standing on the rubber mat, put on a wool mitten and rub it on the film as it goes by at high speed. You can generate enough static electricity to light up a fluorescent lamp tube! On a good, cold winter day I have seen a spark jump almost an inch.

So, I have no doubt that static discharges can ruin film but I, too, would like to run some tests to prove the efficacy of slow vs. fast winding.