The article appears to be almost devoid of information about Google.
My recollection from the time was that GPS mapping wasn't involved and, in fact, the Wikipedia article says: "Mrs. Kim told state police that they had used a paper road map, an account supported by the Oregon State Police, which reported that the Kims had used an official State of Oregon highway map. Mrs. Kim later recounted that, after they had been stuck for four days and were studying the map for help, both she and Mr. Kim noticed that a box in the corner of the map bore the message: "Not all Roads Advisable, Check Weather Conditions"."
I lived near a gorge where there was a nice modern road alongside an old horse track that was only intended for use by the residents connected to it. It was technically two-way (as making it one way would annoy the residents who might want to go either up or down) but barely wide enough for one car. If you met another car halfway, you had to reverse until you got to a driveway you could go into and let the other car past.
At some point Google Maps' algorithm changed and started suggesting that everyone use the old road. There were multiple crashes, and the local government begged Google to deprioritise it, but their answer was basically "our algorithm is always right". Five years on, Google Maps will still suggest it, so the local government added big signs at each end advising drivers to ignore Google Maps and to use the main road.
Although they already weren't suggesting that route, the other map providers (Apple, Here, TomTom etc) contacted by the local government were happy to proactively add a flag to the road saying that it is for residents only - so it will only route using it if the source/destination is that road.