When I read the article I came up with over a dozen questions, none of which were adequately explained. Thus:
Other sources of carbon in the batch- You've got oak, the toasting process, blending of different types of oak/wines, reuse of barrels, different toasted barrels, different types of oak in the barrel, the possibility of a really old oak barrel (neutral) used for fermentation and combination of items such as StaVin's Oak Cubes or Oak Staves, (two different sources of carbon)...
Oak is aged anywhere from 2-3 years before toasting. Toasted oak could be years different than what the year of the vintage is. Oak Trees are significant sources of variability. (Toasting oak releases sugars and flavours into the wine).
Chaptalization is another source- sometimes wines are started with diluted or various mixes of sugar and water to strengthen the yeast growth. You have a grape must that is a little low in sugar- so add more sugar. Where did it come from? Who knows. Probably not beet sugar, if you know what I mean.
Say you have a stuck fermentation- you take some wine out, dilute it, add more sugar, wine, repeat- eventually bringing up the level until the yeast are strong enough to take back over.
Finally, you have blends. To the best of my knowledge a blended wine doesn't have to state the year or can state the year of the major component - depending on the laws of the region.
All in all... not the best article.