This looks false, the Buster Keaton film was released the same year, not 14 years earlier, according to wikipedia. And both were inspired by an 18 year old song, Steamboat Bill, which Mickey whistles at the start.
You have misread the post: it explicitly says that Steamboat Bill was released the same year, "no waiting 14 years"—as in, they didn't wait for the copyright to expire.
The Wikipedia entry implies they're both riffing on the song, not that the cartoon is riffing on the Keaton film.
I guess I'm surprised if it wasn't coincident given only 6 months between releases!
It's also a little confusing how the Lessig refers to the Keaton film as "Steamboat Bill" when it's "Steamboat Bill, Jr." - the song that appears in both is "Steamboat Bill."
You're right that I read it wrong; I'm still not sure if it's correct though.
edit: Having watched them both, they both of course are steamboat themed. Early on, Bill Jr is referred to once as "Willie", and Bill Jr appears to be a musician while Willie is almost entirely musical (using animals as instruments). Those do feel like references. The contents mostly feel unrelated though.
