How to determine if Macbook Pro Retina anti-reflective coating is damaged and/or removed?

Solution 1:

(disclaimer) I'm answering my own question, just in case someone else faces a similar problem, even though I realize the question itself maybe never really belonged on this site.

I had a chance to compare the screen of my Macbook Pro Retina with another (identical) model that does suffer from actual stains, i.e. partially removed anti-reflection coating.

The good news is that, apparently, I did in fact only 'rub off' some very solid dirt, that only looked like the 'stains' that some people see on their damaged screens.

How do I know the other one had a damaged screen?

When I cleaned my screen, I removed some 'silvery' stains, revealing a dark, almost totally black color of the screen/glass. In the case of the other, damaged Macbook screen, the opposite was the case: cleaning/rubbing seems to have removed the dark parts of the screen, and revealed the silvery stains.

How to tell if the coating has peeled off or not?

If you're unsure, the coating is (in all likelihood) still intact. The silvery stains are very noticeable, and while I couldn't tell whether the other screen seemed more reflective or not, I could tell definitely that the stains are not even nearly dark in any way. In other words, when I removed the dirt (as I know now) from my screen, the resulting dark color of the screen when turned off, while not perfectly black perhaps, is drastically different from the damaged parts of the screen, which I can only describe as 'dirty grey/silver'.

Wasn't that kind of obvious in the first place?

Maybe. I'm a bit slow sometimes.