A "lurker" has responded to my RFI, drawing on their experience and knowledge of non-Afghan 'green on blue':
Vietnam had lots of problems with Vietnamese troops attacking Americans, though they didn't make the news that the ones in Afghanistan -- sad as they are -- have made. In one incident (recorded in the archives) a whole advisory team was pulled out because of the danger from the local "friendly" troops. I've heard other stories. Iraq had some, but I the ones that come to mind were insurgents dressed in American or Iraqi uniforms when they attacked Americans, not Iraqi soldiers who did. I lived on an Iraqi base for two and a half years or more and had no problems, though I was always a little concerned when I was somewhere without my weapon and no Americans in sight.
Secondly, returning to Afghanistan, any research and analysis is degraded by the lack of any living shooter being available for interview - either they die at the scene, die later in the follow-up or simply escape - sometimes then appearing in a Taliban video.