Well you tell me! When I said "dangerous" I meant to the fingers/tools/fan blades of those who don't know the fan is not under their control after the bike is shut down.
I did notice that the fan turned on for a very limited time, but this was in temperatures in the 40s. I remain unconvinced that any cooling that might take place after the water pump has been turned off is significant to the longevity of the engine. There isn't any advantage to cooling an all-aluminum engine down more quickly that I can see. If anything, it seems like a rapid cool-down might be a disadvantage.
On the other hand, if you have a car with aluminum heads on an iron block, I can see the benefit of anything that keeps these two at close to the same temperature as long as possible, because of the differential expansion rates of the different materials. That difference puts a huge stress on the ability of the head gaskets to maintain the seal, and without that you of course risk the contamination of the oil with water, which is never good. And even in this case, the water circulation needs to be maintained (which it rarely is) in order to circulate the cooled water out of the radiator and through the block and heads.
I just don't see the point, but I'm always a sucker for a good argument!
Richard