There are some cultures where men are not allowed to speak at all to women in the work place. I believe Arabic or Middle Eastern people are such examples. Technically speaking it may not be legal for a company not to hire someone based on this reason as it would be discrimination based on religion or race. I'm a bit surprised I haven't seen any other answers mention this already.
How long has he lived in North American for? I lived with a man who told me when he first move to the US he had to change some settings on someone's computer. He went into the office and changed the settings without speaking to her at all because he considered this professional. Latter, when he got called in by HR he assured them he had been professional and not spoke a word to her. Apparently in his country it was illegal for men to speak to women in the workplace.