Copyright grants an author of a copyrightable work the exclusive right to make more copies of it. However, if people independently come up with the same exact thing, copying has not occurred and that exclusive right was not violated (and then the court battle effectively becomes one about proving whether copying did in fact occur).

In copyright law there is no such concept as "code snippets that are long enough to qualify for copyright protection" or "canonical owners". Quite explicitly, copyright does not give a monopoly over an idea, but merely protects against the unlawful reproduction of an original work.

If you take some snippet from a work in which you own copyright and find that in the world multiple people have somehow managed to write the exact snippet, but they did it independently without copying it from you, then copyright law effectively states the following things:

1) They definitely aren't violating your copyright, and you have no claim on them whatsoever - independent creation is a complete defense to copyright infringement;

2) Perhaps this snippet might be judged uncopyrightable, as the existence of multiple independent recreations is some evidence that it lacks originality and thus would not qualify for copyright protection at all.