What an interesting description, it does sound like it's possible he did get to the end of the material in many subtests. Keep in mind that even if he did get all the way to the end (if that is what the grey page means) some children get to the end having performed perfectly all the way through, while other kids (like mine!) make careless mistakes along the way (more at the beginning when it's super easy), this means that they don't get maximum points despite having in one sense ceiling-ed the test.
