I recall messaging with a network admin who's French, and over the years I've known him, his English's improved a lot, literally to a point where he typed incoherently with run-on sentences to a point where he can type like a "native English speaker." I believe the ability to speak or write in English gets better over time. I also know this could happen often that a non-native speaker's comes commenting with a good intention but winds up being taken wrongfully or otherwise.