$1,000 is not a meaningful amount of money to Google. Maybe if, based on the fact the entire fleet uses the same software, it is fined $1,000 per car in their fleet each time an incident occurs?
Bear in mind $1,000 per incident is not enough money to justify paying a software developer to fix it.
Well, you can just treat them like they are anybody else. So, $1000 fine plus a point on the license of Waymo. And as suggested by another commenter in the thread, if the cars in the fleet (collectively) accumulate more than 4 points within 12 months, Waymo loses its license. As in, all cars operated by Waymo.
What would justify it? Full years salary of a developer plus their fringe benefits? Probably what $300k fine?
Ticket and require a company lawyer and programmer to show up in traffic court for every infraction and explain current status of self-driving software.
If this behavior actually is a prevalent issue, then there will be many fines that add up. If Google doesn't rack up many fines, then this problem is evidently rare.