He didn't mention that the 430hp was WHP.
At 430 flywheel hp, the lighter 335i should be pretty close to the 500hp heavier M5. hp/lb should be pretty close, and what do you know, so were the cars.
It may pain you guys to hear this, but M cars dont have some magic inside them that makes them unbeatable. They're nice cars, but FAR from untouchable as some on this forum would like to believe.