I watched it last night - that's 1 1/4 hours of my life I'll not be getting back! I should have turned it off as soon as they showed a clip of a 2CV (I guess the Americans think VW made those too).
In defence of VW, all the manufacturers produce software calibrations that achieve their best results during the test cycle and (allegedly) somewhat exploit conditions that are not tested. If you have a steady engine load similar to that of cruising, you can then operate the EGR, retard the injection timing and thus clean up the emissions. As soon as the vehicle hits the road, the load on the engine is changing continuously (if you don't believe me, plug in your VCDS, get on a flat straight road, hit cruise control and watch the engine load continuously change) so injection timing, EGR operation etc is always changing to compensate which really screws up the emissions . If the documentary is correct, the biggest mistake that VW made was retrospectively changing the calibration to look for steering angle input which was a bit naughty.
Even before the VW scandal had happened, this was recognised by both the regulation writers and the vehicle manufacturers who have been collaborating so that realistic emissions would be tested in a test that simulated actual driving much more closely.