You are right.
Saddam could have hired him to produce and distribute the 'gold standard' anthrax.
Or the Martians could have done it too.
Someone who already had access could conceivably have sold out to the highest bidder, for instance. Such a person would probably not have provided production details, thus giving Saddam no long-term WMD capability, just one-shots.
But I don't think this is at all likely.