I think in arenas like that of Robots live the spinner weapons are just banned. however if you are making a flipper that uses a rotating action to flip another robot, I think you could argue this would not be an issue.
The thing is you have to convince the owners, that your particular weapon dose not increase the risk of a robot say being flipped through the arena doors!!
You have to prove safety is not compromised, for a weapon with a flipper speed of about 120rpm radius of 300mm tip speed would be only 3.726 meters per second, about 8.5miles per hour, enough for a heavy to tip over another.