UCI, Valverde & Hamilton

I am trying to understand what is happening with the UCI, Spanish Cycling
Federation, and Alejandro Valverde in comparison with USAC and Tyler
Hamilton.

If I understand correctly, the UCI says that Valverde cannot participate in
the World Championships in Stuttgart because he is named in the Operation
Puerto documents that the UCI received from Spanish authorities. The
Spanish Cycling Federation seems to be saying that they have reviewed the
documents and that they have determined Valverde was not involved. I do not
understand the mechanism that allows the UCI to overrule the Spanish
Federation.

Wasn't Tyler Hamilton named in the Operation Puerto documents? I believe
that there was a copy of a fax sent to Tyler's phone number in Spain with
his wife's maiden name as the recipient. The fax outlined a program of
doping that included multiple products and pricing. I also remember there
being another document associated with the fax that had Tyler's racing
program. With this much evidence how was Tyler allowed to race at the
recent National Championships?