Lots of people have two passports because of dual citizenship, but normally it is in the same name.
Unless this person had changed the way their name read? Converted it from an original ethnic name to a more western version. Or if it was a female, had a passport in their maiden name from another country? I guess there are all types of legimate scenerios.
There have been times when I have had to decide in what name to have my ticket issued.