Thoroughfare vs Feeder Lane Accident

My question involves an injury that occurred in the state of: Colorado

My 17 year old son was involved in an accident in a grocery store parking lot. He was driving parallel to the store in the lane that runs right up front. He was headed east in the "thoroughfare" at 5 mph. Another driver came from a "feeder lane", headed north through the lane my son was driving in. My son clipped the rear drivers side bumper of her SUV with his front drivers side fender. So she had almost made it through his lane when he clipped her. My son was driving very slow which is why I think she almost made it through and the damage was to the rear of her car compared to the front. To my understanding, the thoroughfare traffic have the right of way and the feeder lanes must yield and wait for an open lane. I believe she drove straight through at a higher rate of speed without ever stopping to yield. My son received the ticket and now the lady is claiming injury. He was barely moving when he hit her! I personally feel it was her fault for not yielding to the person who had the right of way. The cop asked my son why he didn't stop when she came through his lane, he never saw her. The reason he got the ticket was because of where the damage occurred on her car. He was looking to the north for traffic and never saw this lady enter his lane. Any help would be greatly appreciated!!

If this person is making a claim, turn it over to the car insurance company.

When you are moving your car forward, you have a duty to look forward to make sure that you are not going to hit something that is directly in front of your car. Your son was so distracted that he didn't even see a car pass almost completely in front of his vehicle, despite driving at so slow a speed that he was "barely moving". Your son can try to argue his case to the insurance company, but it will be an uphill battle -- at a minimum he shares fault.

If he had hit his brake pedal, he would not have hit her at all. Turn it over to the insurance. Both will likely be found at fault.