Given that the unit has been inspected, that's really now the role of the housing inspector; but no, they have no basis to sue you for pointing out actual problems with the apartment.
He's very obviously wrong. Leaving aside the fact that these issues existed when they rented the unit to your girlfriend, such that they are known issues, that's not what the clause says. Further, any lease provision that prohibited a tenant from reporting housing defects to the appropriate housing authorities would be void. See Civil Code Sec. 1942.5.Quoting devilsadvocate3
The tenant is best protected when the tenant makes her own complaint.Quoting devilsadvocate3
If the landlord is ordered to make repairs, the landlord will be expected to make the repairs. If the landlord does not do so, additional consequences or penalties can result.Quoting devilsadvocate3
I'm not going to speculate over a possible rent abatement action for conditions in an apartment that I have never seen.

