Congratulations! What a great story! It just goes to show you that there is no consistency, rhyme or reason in anything USCIS does. After that many years of complaints, new laws, regulations an so on they still cannot get it straight.
I think it's all depends on the person(officer) who does the interview. they all humans and all have prejudices. some are bigots, some open-minded and unless your case is straightforward one (either positive or negative) - they all play role of the judges there.. I was blessed to get that oriental guy in February.. wish I know his phone - would love to invite him to the restaurant..