...Zeroknowledge coins require a "trusted set up". We need to be absolutely sure we can trust whoever set it up...
From the first paragraph of the Zcoin section:
Since monetary inflation of any kind would be detected immediately this also mitigates any trust issues during initial setup.
According to the interview with Gary Le Zcoin does have a trusted setup.
Just after the 30 minute mark or thereabouts.
Unless I missed something
http://www.cryptoholics.com/cryptoholics-ep02/