Based on the timeline of RW on the Fifth Estate, I'm going to say he is not the WR:
1992 Shearwater, Nova Scotia Williams is posted to 434 (Combat Support) Squadron. He works in "electronic warfare & coastal patrol" and flies the CC-144 Challenger the same jet that is used for VIP flights.
http://www.cbc.ca/fifth/2010-2011/abovesuspicion/timelinewilliams.html
He was in Nova Scotia in 1992 (granted it doesn't say for how long), however, seeing as RW was in the airforce, I doubt he had his hair in a ponytail, since that would not be considered an "army issue" haircut.
For an 8-year-old Kitchener boy, the terror took place in a park on Aug. 21, 1992, when he was raped by a freckled-face white man with strawberry blond hair tied in a ponytail
http://www.thestar.com/news/gta/crime/article/726632--cold-case-search-resumes-for-woodland-rapist
A 10-year-old Brampton boy and a 15-year-old Oakville girl were tied to trees during their assaults in a park in
1994 and 1995, respectively.
http://www.thestar.com/news/gta/crime/article/726632--cold-case-search-resumes-for-woodland-rapist
1994 Ottawa Williams is posted to 412 (Transport) Squadron and begins flying VIPs in the Challenger jet.
November 1999 Ottawa Williams promoted to Major and begins a new job working as Director General Military Careers where he served as the multi-engine pilot career manager.
http://www.cbc.ca/fifth/2010-2011/abovesuspicion/timelinewilliams.html
RW was in Ottawa during that time. The timeline does not show anything in 1995, though I suspect he was still in Ottawa seeing as in 1999 while in Ottawa he was promoted to Major.