Hmm...
Lets say the hacker hacked into 2 PCs (A and B and used it as
zombies).
He then used his own PC to send commands to PC A then to PC B then
to ODEX website.
So, if in any case, ODEX trace him back, he will then break off the
connection to PC A.
So odex will only trace back to PC B, and if, just in case, ODEX
manage to trace pass PC B, the hacker would have long disconnected
from PC A (wiping all traces off) so eventually its either PC A or
B that is the scrapegoat.
Besides, he can use unsecured wireless as additional backup.

But, judging from the news, its doesn't sounds that the hacker is
that much sophisticated.