Some people are simply not good at languages, while at the same time they are extremely skilled coders. I know many people like this, in particular Japanese, Chinese and Russian-speaking coders. It's apparently quite a task to learn proper English when your native language is one of these and you weren't exposed to English soon enough.

Dismissing this guy because of his poor English is plain and simply xenophobic prejudice. In this case it came back to the Rails/Github guys and bit them in the ass.