It's completely possible to scratch Gorilla glass. I once got two deep scratches on my Galaxy S2 after a night out. Had not dropped the phone or anything but I suspect it was made by those metal things on jeans. Maybe the phone was pressing against those when I sat down or something.

Anyway I fixed the scratch with Cerium Oxide, the downside is that the grease resistive coating is gone so one area of the screen is a smudge magnet. Solved the issue with a screen protector.

Also managed to get a scratch on about a month old iPad 2, not handling it especially roughly and always used the magnetic screen cover.

I used to be super neurotic about these things. It's much easier to go on living if you learn to accept that electronic equipment always gets some minor scratches and wear marks after use. You upgrade to a new device every few years anyway so it's not worth stressing so much about.