Yes you have so far avoided breaking the license by not even releasing the code coz apparently no one has rightfully requested it
So which one of their customers requested the source code?
It sounds like you admit they were not in violation of the GPLv3
Or why don't you quote the explicit, legal, text of the GPL that they supposedly violated
No, not "the spirit". The literal text. There's a world of difference between "violating a license" and "doing something I don't like"
So ... where did I say they violated the license?
One of my points was that they advertised on their site since the beginning of the year, promoting it being OpenSource.
Yet when they released the Avalon, they hid the modified cgminer source code for a month.