"Remove the perpetual, royalty-free license for derivative work from the contract." I think you're right that author has his thinking switched here. I also obs

"Remove the perpetual, royalty-free license for derivative work from the contract." I think you're right that author has his thinking switched here. I also observe that he didn't make a mistake in translating his thoughts to a blog post. But it's clear to me that the whole contract is a problem.