I have not had that happen, but I have been flung quite high in the air from a freak tree cutting accident. Just yesterday I also flew for quite some time after turning my back on a stone golem (not a good idea).

It just occurred to me that I had a fish (don't remember the type) jump into my longship yesterday, and I ended up falling overboard when I jumped to grab it. I suppose it could have been the fish that knocked me overboard.