you want to here it's not Pena, don't you?
Zabriskie mentions in his report:
"I also recall being in Belgium for a race while on U.S. Postal and Rider-5 and Rider-8, who lived in Spain, came to the race hotel in Belgium even though they were not in the race."
If my research is correct, during his four years at US Postal Zabriskie took part in just two races in Belgium:
Tour de la Region Wallonne 2004 and
Ronde van België 2004 - and in both of them Pena was on the startlist as well and therefor would not match.
But on the other side, in his
E-Mail to Stefano Ferrari in 2007 he says he had worked with Ferrari before
Zabriskie might also have mistaken Belgium with Holland or whatever. And also the length of his name would fit I think