It kind of reminds me of the story of Clare Torry, who did the vocals on Pink Floyd's
The Great Gig In The Sky[1], and received the standard £30 flat fee for session work. Of course the song ended up being a critical piece of an album that went on to be one of the best selling albums in the history of music. Sometimes, we make a big contribution to something and don't end up with a big payoff. It's sad that business shrewdness and negotiating skills tend to have a higher ROI than actual subject matter talent.
Torry ended up suing and they settled out of court, so I guess that's a win.