Accident with a car with no headlights - whose at fault?

I got in an accident Saturday on the Service/Frontage Road that parallels I-49. I was taking a left turn from a side road onto the Service/Frontage road. It's a T-intersection with me having a stop sign and being the bottom of the T and the service road having the right away and being the line across the top. It was about 9:30pm and dark, and the majority of illumination in the area is pretty much from car lights on the interstate as there are no streetlights on the road.

As I began to take my left I was hit on the front-drivers side of my car, by this old arse 2002 Mitsubishi Montero, who I never saw, because his lights weren't on. I tell the officer who shows up this, the other guy obviously protests, but the officer goes checks his lights and based on the condition of the filaments determines his lights were off and cites him for driving with no headlamps, and for an expired inspection sticker.

Now, my understanding through 30 minutes of googling is that because I was taking a left turn and he had the right away, regardless of the condition of his lights, there is a good chance I will be held at least somewhat liable for the accident. I was also told this by his insurance companies claims-adjuster, who I talked with, although I'm obviously skeptical of anything they would say. I've filed with my insurance as well.

I'm just curious if anyone has any experience with this type of situation, and can shed some light on Louisiana shared liability regulations and what I'm likely looking at here.