OED defintion of "gouge" - Concave-bladed instrument used in carpentry, sculpture, and surgery. Cut with gouge; force out eye.
The intent to target an eye appears to have been shown by the proximity to which the injury occurred.
I also didn't see where the glass was first smashed, however it is common knowledge that the impact of (thin) glass with most hard surfaces will be sufficient to cause the glass to shatter, break, or crack.
If the F/O had considered he was being harassed, there are various company, and legal, avenues he could have explored and utilised.
Instead, he decided to take the matter into his own hands.
I don't feel the "battered wives" analogy is a very good one, Voice. Perhaps psychological intimidation by a superior might have been better.
Anyway, this guy lost it, and as a crew member of a public transport vehicle, he has now cast doubt upon his ability to be able to work in harmony, and safely, in that type of environ, imo.