veery wrote:Exactly - if the headlight switch is not set for automatic, then the lights could be off. You may be able to estimate the threshold, but can you show what position the switch was in.
And there you have it. My car is a later model, and the auto lights come on in cloudy situations quite a bit, but they don't come on when you turn on the wipers, as required in my state. So I frequently have to switch them to "On" position for rain, and frequently miss getting them back into auto when I intend to, ending up in "Off" position.
Good luck with the case, OP, but it's really a "he said/she said" situation unless there's a third party witness who says the lights were on or off. In the absence of one, the other driver would actually be in a better position to state whether your client's lights were on or off.
Of course, I'm not a lawyer, just a guy who's been driving for 46 years.