I am unsure if rewards in this sense means the project itself or just the incentives. In any case, he's fulfilled neither. Here's the text from KS:
"Is a creator legally obligated to fulfill the promises of their project?
Yes. Kickstarter's Terms of Use require creators to fulfill all rewards of their project or refund any backer whose reward they do not or cannot fulfill. We crafted these terms to create a legal requirement for creators to follow through on their projects, and to give backers a recourse if they don't. We hope that backers will consider using this provision only in cases where they feel that a creator has not made a good faith effort to complete the project and fulfill."
"Is a creator legally obligated to fulfill the promises of their project?
Yes. Kickstarter's Terms of Use require creators to fulfill all rewards of their project or refund any backer whose reward they do not or cannot fulfill. We crafted these terms to create a legal requirement for creators to follow through on their projects, and to give backers a recourse if they don't. We hope that backers will consider using this provision only in cases where they feel that a creator has not made a good faith effort to complete the project and fulfill."
It also cites this image: https://ksr-assets.s3.amazonaws.com/creator-responsibility.p... which I think describes this situation pretty well.