This is obviously more recent than 1971, but here are the 1997 National Guard regulations. Take a look a 4.17. GWB is in the clear assuming these regulations are similar to what was in effect in 1971.
http://www.dtic.mil/whs/directives/corres/html2/d123513x.htm
"4.17. Individual Reservists who are qualified for retirement under Chapter 1223 of reference (a), except for having reached 60 years of age, are required to attain 50 points each anniversary year to be retained in the Ready Reserve, including the IRR, or the active status list of the Standby Reserve. Waiver of that requirement on a one-time basis may be made by the Secretary concerned or, in the case of members possessing critical wartime skills, by a waiver granted by the Assistant Secretary of Defense for Reserve Affairs. "