You're implying that minimum following distance <= stopping distance. A brief Google search yields a stopping distance of 315 feet for travel speed of 70 mph.[0] We don't train drivers to leave a football field of space in between cars traveling at highway speed. At least where I live, the legal standard for minimum following distance is that a driver "shall not follow another vehicle more closely than is reasonable and prudent".

If Driver #3 can't see Car #1 past Car #2, and Car #2 is traveling at highway speed, I think it's a stretch to say that Driver #3 could be faulted.

[0] http://www.driveandstayalive.com/stopping-distances/