How did Linh end up working for Sam Darrow?

The next morning bombs went off and Linh's village was destroyed as was his family. Linh saw no reason to stay and deserted the SVA. His first months in Saigon were a blur. He survived but nothing more. One day Linh saw a sign advertising help wanted. Linh said he was a friend of Darrow's and was hired. Linh was sent to Cambodia.