Spinning Slinger Ring When Motor is Off

We have a pair of electric condensate pumps located beneath the condensor of a 120MW turbine. One of the bearings between the motor and pump developed some strange markings on the shaft and bearing. The markings were a mirror image of each other between the shaft and the babbit. It looked like it could have been caused by electric current so we did some things to eliminate stray current.

Now we have noticed that the slinger ring is moving when the motor is off and not spinning. We only noticed the movement at 28MW (it stopped when we looked later at 65MW) but the vibrations seem about the same (to my calibrated fingers).

I now suspect that the markings have come from the shaft vibrating on the bearing when shut down. My question is twofold; first has anyone ever seen anything like this before, and second, what is it about vibration that causes a ring on a shaft to spin like that? I might open a second discussion for the cause of spin.

Drew K