Is their work present in v7?

Yes. The AI operator posted this as the prompt: https://github.com/chardet/chardet/commit/f51f523506a73f89f0...

which, minimally instructs it to directly examine the test suite: `4. High encoding accuracy on the chardet test suite`

So what? Is reading code the same as copying code or modifying existing code?

If you want to prove you did not make a derivative work, yes it helps if you never read the source code. Hence so call "clean room" implementations.

Why should I prove that? Let those who claim the violation prove that.

There is plenty of evidence already. The claim has been substantiated.

You can't just dismiss it then say the claimant has to provide proof.

Yes. Commits clearly show in progress where both LGPL and MIT code was working together. This clearly show they are a derivative work and MUST follow the original license.

Plus the argument put forth is that they can re-license the project. It's not a new one made from scratch.

So, if these commits were private and squashed together before 7.0 was published there would be no violation?

The commits being public or not does not change the fact the developement was made as a derivative work of the original version.

They would be concealing the violation.

Consider TCC relicensing. They identified the files touched by contributors that wanted to keep the GPL license and reimplemented them. No team A/team B clean room approach used. The same happened here, but at a different scale. All files now have a new author and this author is free to change the license of his work.

Did they eventually remove/replace all the LGPL code?

No because the "new" code is LGPL too since they developped it as a derivative work of the original. They cannot license it MIT as it is LPGL.