The 37-year-old was indignant about the handling of "Operacion Puerto" as six months after the scandal was revealed, Discovery Channel proudly presented Ivan Basso as their new team leader.
The "zero tolerance" that Zabel demanded in an inteview with eurosport at the end of May has not occured as the legal repercussions have blocked those urgently trying to address the shadier side of the sport.
He said: "In view of the development of this affair perhaps heads should roll within the UCI or WADA."
Petacchi gains revenge
But Zabel could draw a positive view from a personal perspective of his season with the Milram team.
He said: "We can be quite content, even if everything did not run naturally as desired and we had to bear for instance the long loss of Alessandro Petacchi - nevertheless we achieved much.
"For me back-to-back successes in the autumn were very important," said the world champion runner-up and double stage winner of the Vuelta.
But Zabel is quite candid about his plans for 2007.
"In December I will build myself up with the team, then we will decide together on the plans," he commented.
Pro Tour 2007
Petacchi seals victory
Wins for Petacchi, Karpets