Stuart and Deffeye aren't measuring the same thing for the peak.  Stuart is looking at peak production while Deffeye is defining the peak at 1/2 of the total possible production.
You guys familiar with "fuzzy logic?"

I think the math is all good (and thanks to all who work so hard at it!), but I think we can step back and with a "fuzzy" eye say that the math, the news, and crazy things like the State of the Union address ... are telling us "peak oil" is (fuzzy logic) true, right now.

..which I believe is another way of saying that Stuart is looking at actual production data peak, while Deffeyes is talking about the smooth curve-fitted peak via Hubbert.