I'm pretty sure the member has to do it. We rented in June and the person we rented from added ME for us; she told me she had to because she is the member and I'm not.
The DME person made a mistake unless the policy has just been changed. If you listen to the DME phone announcement when you call, it specifically states that DVC booking must go through Member Services.
Others shouldn't expect the same result if they try to book directly.