I wouldn't be so worried about the lady who ran the stop sign. For all you know, she's sitting somewhere right now racking her brain trying to figure out how she's gonna sue your s/o..
For example...I got rear-ended not so long ago, and things didn't turn out so well for the rear-ender's car. She was in a brand new Toyota Yaris, I was in a Toyota T-100 with a frame-mounted trailer hitch.. I got a dented bumper, she got absolutely destroyed.
It was all pretty cut and dried, too... I was at a dead stop behind three other cars at a redlight, she didn't stop, blammo. End of story.
Well, I got a call from her insurance company asking for my statement on tape...standard procedure...if I didn't talk, they wouldn't write me a check. I cleared it with my insurance company beforehand, and given the nature of the accident, they weren't too concerned that I might "screw up" and say something indicating any culpability on my end.. It was open and shut, so far as they were concerned.
So -- very, very guardedly and in as few words as possible -- I answered her insurance company's questions. Lots of "yes" and "no," only answering precisely what was asked and offering not a shred more.
Only after the insurance rep turned off the tape did she inform me of the claim that I had veered over in her client's lane and jammed on the brakes at the last second, making it impossible for her to avoid hitting me.....almost like I did a "swoop and squat."
Why would she lie like this, you may ask?
Because -- in her infinite wisdom -- she scrimped and saved up enough money to buy the car outright...cash money...then decided it would be a good idea to carry liability only. Ya know...save that $25/mo it would cost a late-20's asian female to upgrade to full coverage on a piddly little $13K car..
As it happened, her insurance agent was a high school friend of mine.. He told me -- point blank -- that he'd warned her and chided her for not carrying full coverage when the cost difference was so seemingly inconsequential....but she wouldn't listen. So, when she came in saying she'd rear-ended someone and asking what she should do with the car, I think he got a tiny bit of satisfaction in saying:
"Well, I guess you sell it for scrap."
Anyway...the long and short being that this sweet little girl who was so apologetic for hitting me turned into a lying, conniving, deceitful little turdmonkey when she saw the repair bill..
My advice: Eat, or be eaten. Go on the offense RIGHT NOW, before she does. Threaten her with a thunderstorm of poop so massive that she will feel genuine relief when you reluctantly agree to knock it back down to a mere $4K..