Much of this depends on what this guy was allowed to examine.
For example, suppose a home inspector is hired to inspect my house. But I absolutely refuse him access to my basement. Based on what he was allowed to see, the home inspector says that my house is in excellent condition. But is it really?
Yes, it sounds like he was looking for computer hacking. If the fraud involved mailing in fraudulent ballots, he wouldn’t have detected that.
Or like a store owner claiming there is no shoplifting in his establishment but refuses to audit his inventory.