Yes, generally a 'diesel' lacks that ability to really change tempo and have those quick accelerations, but they can go steady for long periods. I thought it was a little more related to slow and fast twitch fiber composition (a really fine detail, because even a sprinter on the road, like Cav, is much more an endurance athlete than a pure fast twitch machine).To me it's someone that can't really sprint but can keep a tempo pace up for hours and hours and hours.
Also, VO2 is not the end all and be all, but it is a ceiling and if it is too low, then even insane lactate clearance, etc., will not save you in an aerobic sport. IMO in modern cycling, if a man has a VO2 below 70, at race weight and in race condition, then they are not going to the WT.
Lots of athletes are FoS though and sometimes just guessing at numbers. Also, he might have been confusing his absolute numbers and his VO2 with consideration of his body weight.