I'm probably being really thick here.
I thought ePO worked by increasing the red blood cell count so the body accepted more oxygen.
If you do a blood transfusion so your levels stay the same and you don't show up in the doping tests, doesn't that mean you've just taken all the "goodness" out of your body and replaced it with the "duff" blood you used to have?
I'm glad I just commute, audax sometimes, and ride for fun. This doping to race really is a confusing subject.