Gary, I would say having your camera randomly stop performing and be unable to turn it off using the on/off switch is a defect.
Imagine if your car did that. So, pop open the hood, hop out of your car, disconnect the battery cable, reconnect the cable, slam the hood and restart your car. Obviously, a camera isn't on the same level as a car, but a defect is a defect.
I'm not sure about anybody else but when I spend $6000 for a camera I expect major defects to be resolved before production starts. I, too, own a D7000, and I never heard of the problem you mentioned. D7000's did have a problem with white spots on low light videos that was fixed by a firmware update.
Jack, You definitely lose the last image when the camera freezes. I'm not sure if during a motor driven sequence, if you lose more than the last image.