In doing research on the DOT's use of chipseal, or more specifically on how cyclists in the area can respond to it, I've found that the Washington DOT has a claims office for damages resulting from 'negligence' in DOT work. Yakima County also has a claims office, and each year they get a couple of claims for damaged windshields from the gravel off chipsealed roads. That doesn't mean they pay the damages, but it does mean a claim can be filed.
Since the DOT here has already acknowledged that they used the wrong size gravel, and the county commissioner is aware of concern by users of the road over safety issues, seems to me they've opened the door to having to compensate for personal and property damage to bikes, motorcycles, and cars and trucks. This would be a strong incentive for them to redo the road properly, unless they are extremely attached to being liable. A letter to the editor could make people aware of this.
I'm going to try to find out more about the claims process tomorrow when govt. offices open.