Just out of curiosity, would such genetic disposition make him a better or a worse fit for the job? Would the people of Galicia be proud that one of their sons works for Firefox or would they be ashamed?
There was nothing wrong with his question. Your not-so-subtle implication of racism is inappropriate. Some people are simply interested in language and names.
I've never seen the surname Teixeira before and I also wondered the same thing, since "eira" suggests Portuguese but the 'x' seems like Nahuatl or Mexican Spanish (like Tlaxcala).