Is the client looking out for Kevin's interests?
My previous comment wasn't intended to say that Kevin should look out for the client's interests, but rather that, by establishing the terms of the project up front, he's protecting
his own interests. By taking the approach he has chosen, he opens himself up to the risk of clients sending in their lawyers to say, "Under standard copyright law, this is a 'work made for hire'. There is no agreement in place to override that. Therefore, we own the copyright, not you. You
will turn it over immediately and, furthermore, you will pay our legal fees plus damages related to your attempt to prevent our lawful use of our property."
Now, I'm not competent to establish whether it actually is a 'work made for hire' under copyright law or not in his (or any other) jurisdiction, but that's beside the point. If he has to go to court to defend against such a claim, he loses, period. Even if he wins the case, the legal fees and non-billable time spent on it will add up to a high cost for doing so.