That's because day 1 no longer counts against the 70 hour limit (you are only required to count the current day and the previous 7 days for 8 days total). Since the driver had -5 hours available and 10 hours fell off the calculation, the driver had a total of 5 hours available on the 70 hour limit.
How many countries are there in the world? Since South Sudan became an independent state on 9 July 2011, there are now 195 independent sovereign nations in the world (including disputed but defacto independent Taiwan), plus about 60 dependent areas, and five disputed territories, like Kosovo.
World population is expected to reach 8 billion people in 2023 according to the United Nations (in 2026 according to the U.S. Census Bureau). The current world population is 7.5 billion as of March 2017 according to the most recent United Nations estimates elaborated by Worldometers.