In cases like these, you need to rely on the photographer, they are the ones who will know there is a license. So him relying upon the client, who might make a mistake, wont necessarily be the end of him as you point out, which I agree with. These photographers do not have agents, and to the extent they did, it'd be Getty, who pays them less than $5 for perpetual web-use licenses. That's why so many of them leave Getty. Getty then continues to offer new licenses for the photographs, despite their contract being terminated. The article seems to mistake that as well. I'm a copyright attorney and we have the opposite approach of Liebowitz.