It sounds as though they allowed the middle name to contain a space, which doesn't match my mental model but perhaps that's how they do it in California. It invites the question: do they allow a first name to contain a space, so that ("X", "AE A-XII", "Last Name") and ("X AE", "A-XII", "Last Name") are different names?
EDIT: The funny thing isn't allowing spaces in a middle name; it's have a separate field for middle name(s) at all. Modern passports have just two name fields: "surname" and "given names". Both may contain spaces. But according to images on the web, Californian birth certificates really do have three name fields.