With the BRS golf course across the street from the 7/4/69 attack I wondered if Z could be a regular golfer in those days . He mentioned skin or scuba ? diving once so that may have been a activity he was into. If he has a sever limp , or damaged muscles you want to exercise to strengthen as much as he could take golf may have been the other activity he could easily do.

I assume there were golf courses close by the sites in the 69 era.
http://www.presidiogolf.com/golf/parking/
looking at the Presideo course I saw this sign odd huh