Different laws in different states.
Not to defend to Kwik Kar employees (I used to be one), they are just doing their job on inspections. The laws states that there can be no tinting, aka, blackouts, on the front or rear lights. Clear lenses are only okay if the lights themselves have the proper colored lenses or are themselves amber (signal) or red (brake/tail) in color.
I believe tint has to actually have 30% visibility on the driver and passenger front doors. Windshield tint visors cannot be below the DOT line that is marked on every windshield, and cannot not be colored ( I think there were a couple colors that could pass). Tint any where else on windows does not have a regulation.
They guys at the first place are just covering their ass, I was a state inspector for 10 years, and you dont want to get caught by a DPS test car. Lose your license, get fined, and possibly jail time.
Next time you get an inspection and someone is scrutinizing over every little thing on your car, you should be thankful. It is people like them that are keeping safer cars on the road. Also keep in mind if they pass your inspection, you kill someone in a car accident, one of the first things the police look at is the inspection sticker. If it is new, and they determing the inspector passed the vehicle overlooking something that caused the accident, the inspector is now liable for the death.