I believe the fact that Jeff moved the contrast slider to the left at that point was simply to show that Contrast may be adjusted negatively or positively. It is important to judge contrast early in the Develop process.
Neither is 'correct' or 'incorrect' - the user must decide on the look that they want.
The main point being made by both Jeff & Michael is that imports of raw images under Process 2012 require the user to pay more attention to Contrast than in the past.
When Michael states that images are imported 'flatter', Jeff adds, "Well, yes, flatter, or different!"
The point being, that from Lightroom 4 on, Process 2012 tends to import files looking slightly different than earlier processes (2010 & 2003)