It all came down to the final race of the season, where Hamilton needed to win and see his rival finish off the podium to take the title.
The Brit drove slower than the car's capabilities to try and push Rosberg into the chasing pack, despite several demands from the Mercedes pit wall to speed up.
Hamilton's slow pace allowed Sebastian Vettel and Max Verstappen to close to within of second-placed Rosberg, putting his race and championship result under threat.
"Lewis was putting our team result in jeopardy at the last race because he was backing everybody up including myself, to give him a chance for the championship," Rosberg said.
"But it went against that exact rule that we had. And that's why as he was going slower and slower...the team was using this rule and saying, 'Lewis, you have to go faster now, or let Nico past'.
"And he did not respect that then. Which is, of course, in a way understandable, because it's coming down to the line and the world championship is at stake.
"But considering I moved out of the way in Monaco...
"What happens [if you disrespect the rule]? You don't get a fine or anything, but the team is very, very disappointed with you."