Good point - the wording I chose should have qualified the scope in that first statement: how about something like "as the scope that is reproduced verbatim increases, the likelihood of infringement approaches 100%?" (excluding prior art, public domain, etc). Obviously no one could reasonably claim copyright on a variable declaration - the scope is too small, and in some languages there is only one way to express it.

However, the statement was only for cases of verbatim copies produced by Copilot. The AFC Wikipedia article states that "Proving copyright infringement requires proving both ownership of the copyright and that copying took place." The 3 detailed tests developed in that case appear to be "expand" the determination of infringement to close potential loopholes where, while there is not a verbatim copy, infringement is still deemed to have occurred because of "substantial similarity". e.g. someone copies a program but changes the variable names.

So where is the line between infringement and not, in cases where there is an exact copy of a code fragment? Can we still use the utilitarian defense or is that only used by the court to exclude portions of the code in the tests for "substantial similarity"?