If they come to Nova Scotia, they would of course need to be on the CR.
My understanding, however, from what is being stated is that the psychologist has been asked to review the work of another provider but would not be interacting with the actual client who was the subject of the file review. This work will be conducted outside of NS. If this is the case and the psychologist is not hired by a client/firm/organization located in NS, then we would not typically consider them to be practicing here.
If there is much likelihood that the psychologist will comes to NS then there would be no harm in being placed on the NSRP courtesy register.