Rider 19 comes from these 3: Michael Barry, Victor Hugo Peña, Steffen Kjaergaard.
Zabriskie wrote: "During the 2002 Vuelta my roommate was Rider-19. He began to feel badly and evetually dropped out of race. After Rider 19 had left competition, Johan Bruyneel came to the hotel room I had sharing with Rider-19 in which we had a small refrigerator and took out a box wrapped in black plastic."
Barry, Peña, Kjaergaar were only ones from USPostal, who did not finish the race. I guess he is not talking of Barry.