Key_message_vod__c records have a Private sharing setting that is shared among different groups within CRM. Users that belong to one group are seeing Key messages from a different group.
For example, one user belongs to the group with a Country code of UR. However, this user is seeing records with Country code as US as well. When viewing Reasons for Access, the Administrator is listed as the Reason for Access.
If the Reason for Access is an Administrator, it means that the user has admin permissions. Both the user profile and the user Permission Set need to be analyzed to verify that View All object permissions is not granted for this object.
CRM Help Documentation: N/A