What I said was

[It] isn't "plagiarism" if you give credit.

This is different from saying "If you don't give credit, it's plagiarism."

Put another way: it is sufficient for something to not be plagiarism if all materials are credited, but that doesn't necessarily mean everything that doesn't do that is plagiarism per-se. It is beyond the scope of my musings to reckon the minimum requirement of non-accreditation for something to qualify as "plagiarism".