I'm reminded this week of a void in the GIPS(r) verification guidance regarding what to do when a new verifier finds problems that the old verifier didn't. I understand that this will be addressed in the future, but right now there's no guidance.
Let's say that Verifier A verified Firm XYZ for the period 2000-2007 and issued a verification report, suggesting that "all is well." Firm XYZ decides to replace their prior verifier with Verifier B who conducts the verification for 2008. During the course of their review Verifier B finds several problems which likely didn't just arise, but were most likely present for the prior period that had been reviewed by Verifier A. What happens next?
Let's say that the firm corrects the problems for 2008: can or should Verifier B issue a report? I believe the answer is "no." Although the firm's records are correct for 2008 and although Firm B didn't have anything to do with the prior verification, they should seek some assurance from the firm that they have gone back and corrected the prior period, too. They should request, in writing, such a statement. Since they hadn't been hired to verify the prior period they wouldn't be required to validate anything; they can rely on the client's word. If for any reason the verifier feels uncertain, they can indicate this and withhold their report pending satisfaction of the verifier's concerns.
I believe that this is what we'll find to be in the upcoming guidance, or something like that.