Can't respond to your first point as I don't really know, but I've only used those lights about three times in the lifetime of the car, so wear and tear is a hard thing to state. Proving anything is anyone's fault is an issue whenever insurance is involved, and generally comes down to trusting someone's word.

I definitely would take the car to another shop to get fixed, and the FlightCar rep knew this. The disagreement was not over price, it was over whether they'd cover repair at all.