Continuity mistake: When Pyle comes to Fowler's place on the night of his assassination his dog leaves a footprint in the uncured concrete in the hallway where some tiling work hasn't been finished yet. In close-up the line of tiles at the border has a step that wasn't there before.
Trivia: The officer speaking French is true to historical facts: it was mainly the French Foreign Legion fighting in Indochina at the time. However, the troops were predominantly of German origin (ex Wehrmacht and SS soldiers) and there is no detectable German accent in their French. True, this could be a fully French unit, thus no mistake. In live movies and interviews from the time, German accents in French are common.