When a SharePoint 2013 server has Italian Regional Settings and the Change Auditor Coordinator has US Regional Settings, SharePoint events do not appear in search results.
The events are not returned in Searches because the Time Detected for the event is is recorded as 1970-01-01.
On the SharePoint server, change the Date format to DD/MM/YY and the Time format to HH:MM:SS. Then reboot the server. It is unknown how this may impact SharePoint.
Issue fixed in Change Auditor 6.7.1497.