Let's not forget that Lewis would have been 6 seconds further up the road than Nico if not for his silly pitstop blunder. Perhaps it was this that put Nico on Lewis' tail and perhaps they started on the same fuel. That six seconds might have been gained through burning more fuel earlier in the race on a juicier engine map.
So perhaps, had Lewis not blundered and lost those six second, the whole thing might have been a non-issue. Still, Lewis' mistake but none of us know the fuel levels each driver started with. All we know is that Lewis had less at the later stages of the race.
Only a theory but it gives us something other than the fuel loads to look at and, in Nico's favour, perhaps Lewis was saved from his own blunder in the pitbox rather than the teams blunder with fuel calculations.