This guy thought he found something and tried to share it - probably not completely benevolently (he wants hits on his videos, right) - but nevertheless, there was a "public" capacity to what he did....
That said, he can't say - categorically - that it's not sapphire, nor can anyone else, unless it's tested properly. Ideally you'd want to be getting a lab report if you're going to claim a huge multi-national company is lying..... Just, ya' know, to cover your own back.... Until it's proven though, it's just a claim - and it's likely that it is a misinterpreted claim.
A coating is the most likely explanation. "Why would they do this" people ask? Well, it's for different reasons - anti-reflection does a fundamentally different job to something that's providing scratch resistance. One of the two things would always have to be harder or softer than the other.
Ultimately which would you want to fail first - the coating (which could be removed, not be quite optimal - but still work), or a big dirty scratch that would require the whole lens to be replaced?
This said, if a razor blade can't damage either - then I'm happy. Others? That's their choice to make!
Just as on prescription eye glasses, many of us have both scratch resistance and anti-glare coatings added, it really is no different.
Remember folks.... Controversy = clicks = $$$ + fame.....
(It's not "something seems up with the lens, what could it possibly be - let's find out scientifically..." it's "Apple LIED!!!!!"....)