HI Terrib
Continuing to question the doctors until you understand is important for you and your husband. Doctors never know if they are facing people like your husband ("just tell me what time I have to be there") or yourself ("yes but why and what are the options?")so may well err on the side of caution and answer only when asked until they get your measure. They may also be pulling their punches while your husband is within earshot (although Alex's doctors never did

).
Alex and I also had a complete response to the first part of treatment, although in our case it was chemo rather than surgery. So radiation was targeting a "tumourless" area. Our doctors told us that there may be residual cells in the area that were too small to be picked up on scan or examination and previous experience had taught them proceed with the radiation to blast any residual cells and hopefully avoid recurrence.
Regarding the extra radiation: Alex and I were also scheduled for chemo dose after radiation was complete. I questioned this as illogical and the chemotherapy oncologist agreed. Consequently, the last day of Alex's treatment was the last dose of radiation.
Karen