Kimi passed Nico Rosberg then under a waved yellow and Nico was definitely on the track at the time!
And you can get close enough to the car in front to not be affected by the turbulent air, and instead get a slipstream, hence why you see F1 cars getting behind the car in front until the last minute and then ducking out and getting past.
I wasn't refering to the slipstream prior to the overtake.
That is the whole point that he was close enough to be in the slipstream due to the fact he tooh a shorter route and completely missed out a courner completly.