The way I read it he thinks the Bf 109's contribution prior BoB wasn't significant enough, whereas the Spitfire's contribution in the BoB was. Granted the BoB was a pure air battle, I don't think the bigger picture would've changed that much with the RAF only operating Hurricanes. To see whatever happened in '41 in the air over western europe as a defeat of the LW or the Bf 109 in particular is extremely misleading, to say the least.