CJ makes most of his errors due to nervousness brought on by peering over the next cliff. For many authors, the errors arise from a lack of attention to their work. Most of them know the grammar rules, spelling, etc., but don't take the time to review. Most of us readers, tend to insert the correct word, spelling, or punctuation and never notice the error; we know subconsciously what the author intended to say.
Our education system bears a lot of the blame by not emphasizing the grammar rules. Teachers want students to express their thoughts and emotions and overlook the fact that what is put down on paper may be incomprehensible. Insisting that students comply with all the rules may injure their precious little psyches. Schools, at least in the US, should institute an EFL curriculum. That's English as a first language.
As for the bonus points, all I can see is that BlueSox may have intentionally used "in" rather than "or"; the description should read "Do they speak English or What?"