[5][6] In the late 1980s and early 1990s, Walker trained Karen National Liberation Army insurgents on the Thailand-Myanmar border, where he met his wife in a remote northern Thai village.

[7][better source needed] In the early 1990s, Walker was co-producing an independent feature film he had written, The Man from Year Zero with actor Haing S. Ngor from the movie The Killing Fields.

Walker's screenplay described how Cambodian refugees in Canada encounter a former Khmer Rouge executioner hiding among them and was going to feature Ngor in the role of the fugitive perpetrator.

As many of the Khmer Rouge perpetrators had returned to Cambodia in the 1990s, and re-entered government service, police, military and business, and were now claiming that they "had no choice" in perpetrating their crimes under Pol Pot, Walker's proposed film about the one Khmer Rouge functionary who demonstrated they did have a choice and survived Pol Pot just the same, was met with hostility from some sectors in Cambodia.

[citation needed] Walker's body was recovered by his ex-wife's family, cremated and his ashes enshrined in the northern Thai village where he had met his wife, as per his wishes.