@ogeist The copyright infringement (if any) will be at the point of copying and distributing the book.

For example if I went out and photocopied this guy’s entire novel and stapled it together and gave it to you, that’s technically copyright infringement.

Has nothing to do with what you or I write ourselves subsequently except if what we write proves that I must have copied the book and illegally distributed it then that could be evidence.

Plagiarism is not the only kind of copyright infringement.