Yup, the long exposure NR is turned on, which basically takes a second exposure with the shutter closed to map the hot pixels and then subtract them from the frame. Mine does it on 30 second exposures on the first one and so long as the setting don't change and power is still on, it reuses that info on other successive frames with long exposures. Otherwise, it will do it again if things change or the power cycles off...all normal operation for the camera.
Mike, thanks for the feedback on the shot! I did do an up-painted version too which isn't quite as wild looking...
Cheers!