The way I read it, the test cases weren't really the problem. The RIAA was alleging that the purpose of youtube-dl is to circumvent DRM and they try to back this statement up by pointing out that copyrighted works are being downloaded in the test cases.
Here is a bit of a discussion about it by seemingly knowledgeable people:
> > the source code expressly suggests its use to copy and/or distribute the following copyrighted works owned by our member companies:
> > Icona Pop – I Love It (feat. Charli XCX) [Official Video], owned by Warner Music Group Justin Timberlake – Tunnel Vision (Explicit), owned by Sony Music Group Taylor Swift – Shake it Off, owned/exclusively licensed by Universal Music Group
> Complainants are "confused" about actual infringement (which is prohibited by copyright law), and creating a method for infringing copyright. Under DMCA and US copyright law, copying is infringing, programming is not infringing. The complaint does not clearly allege unauthorized copying of another person's intellectual property, and their complaint is based on the theory that certain programming actions constitute copyright infringement. I don't actually think they are confused, I think they are testing the boundaries.
Hmm they seem to be taking it from the approach that RIAA was sending a takedown on the grounds that youtube-dl was infringing on the copyright of their members, but that doesn't seem to be what the actual takedown claims. Instead it's requesting takedown on the grounds that youtube-dl is breaking protection measures in violation of 1201, and the answer given doesn't really address that except to say that breaking protection measures isn't infringement (which wasn't what they claimed in the first place).
EFF represented youtube-dl to get the repository reinstated, and their lawyers instead tried to prove that YouTube doesn't have DRM, and that the test cases provided were neither suggesting other people to infringe, nor infringing themselves (falling under fair use). The full response is here: https://github.com/github/dmca/blob/master/2020/11/2020-11-1...
Here is a bit of a discussion about it by seemingly knowledgeable people:
https://law.stackexchange.com/questions/57421/is-youtube-dl-...
> > the source code expressly suggests its use to copy and/or distribute the following copyrighted works owned by our member companies: > > Icona Pop – I Love It (feat. Charli XCX) [Official Video], owned by Warner Music Group Justin Timberlake – Tunnel Vision (Explicit), owned by Sony Music Group Taylor Swift – Shake it Off, owned/exclusively licensed by Universal Music Group
> Complainants are "confused" about actual infringement (which is prohibited by copyright law), and creating a method for infringing copyright. Under DMCA and US copyright law, copying is infringing, programming is not infringing. The complaint does not clearly allege unauthorized copying of another person's intellectual property, and their complaint is based on the theory that certain programming actions constitute copyright infringement. I don't actually think they are confused, I think they are testing the boundaries.