Any lawsuit on this would be frivolous. Mapping firms are not responsible for determining safe travel *conditions*. Evaluating travel conditions and your skills and your vehicle's capability to handle those conditions at any given speed are the individual's responsibility. This is why you can get a ticket for doing the speed limit in hazardous conditions that are unsafe for that speed - you're expected to know better.
No offense to the family, but Mr. Kim's reliance on technology would seem to have supplanted his common sense and good judgment.