I suspect that what they were getting at was more the small electrical sub-components which are used in building PCBs
The fake capacitors and such like, made by the million and knocked out in Chinese copy shops and almost impossible to ID
Its been a problem in the computer industry for years, despite the QA checks. Event the majors such as IBM, Dell, HP, Intel were caught out (and still are being). I don't see the situation being any different with aircraft electronics: a circuit board may well be a genuine part from whomever, but are the components on it genuine? How do you check? I don't think you can, unless your QA trail can follow the parts source to each individual component, and thats pretty unlikely given the nature in which such parts are traded