Seized engine

If you were traveling down the road when your engine seized it would lock up the drive train and not allow the wheels to turn. The momentum of the vehicle would cause the wheels to want to continue turning. These two opposing forces would put a lot of twisting motion on the drive train. If your CV joints were the weakest link in the drive train, then yes, I can see one or both of them breaking. Brakes are meant to stop the wheels quickly, CV joints are not.