Why exactly are the BEA being tasked with this investigation, as regards FDR/CVR ? because the wife of a French diplomat was on board ?
Just because they have the expertise?
History and language would be two possible answers. After World War I the League of Nations transferred control of many territories from the losers to the winners. France was given the mandate for Syria, of which Lebanon was a part. As a result, French is still a conditional official language of Lebanon.