Rubuta ci gaba don wannan sakin layi - Blair daga baya ya rubuta cewa Serong ya yarda da kare Kudancin Vietnam daga kwaminisanci a matsayin "aikinsa na sirri", kuma shawarar da ya yanke na yin ritaya da wuri ya kasance saboda karuwar sa hannu tare da kungiyoyin Amurka, da darajar da suka sanya a kan aikinsa da martabarsa a matsayin mutum na duniya, da kuma karuwar "nesa da motsin rai" daga Sojojin Australiya da manyan shugabannin sa. Daga baya ya rubuta cewa ya "... sami hanyar da za ta kasance mafi yawan sabis ga kasar a waje da ita fiye da ita. " Serong ya zauna a Kudancin Vietnam a matsayin mai ba da shawara kan tsaro da leken asiri ga gwamnatin Vietnam. Ya kuma koyar a Kwalejin Tsaro ta Kasa ta Kudancin Vietnam kuma ya yi aiki ga kungiyar Rand, Cibiyar Hudson da sauran kamfanoni, suna shirya nazarin dabarun. Ya kuma kasance mai ba da shawara ga Pentagon da ƙungiyoyin tsara manufofin shugabannin Amurka da yawa, gami da gwamnatin Nixon. A shekara ta 1971, Serong ya bayyana cewa Kudancin Vietnam ya ci nasara a yakin. Ya kasance bayan da sojojin Australia suka janye, ya ci gaba da aiki a Kudancin Vietnam har zuwa Fall of Saigon
Ka yi haƙuri. Serong ya bar Saigon ranar da aka kama shi, ya bar jirgin sama a cikin jirgin sama na karshe daga ofishin jakadancin Amurka a ranar 29 ga Afrilu, 1975. Ya karɓi lambobin yabo da yawa na Amurka da Kudancin Vietnamese, gami da Legion of Merit na Amurka, lambar girmamawa ta (Vietnam), Gicciye na Gallantry (tare da dabino), da Knight na National Order of Vietnam.