Who Is Affected
This bug may affect users of the Gmail email program.
Description of Problem
When clicking on the ‘more details’ link on individual entries in the calendar, users who are currently logged into the Gmail email program may find that their personal calendar opens to display the requested details.
This is obviously irritating but …
… it does not affect the security or privacy of your personal calendar.
The calendar is displayed only in the browser you are currently using and cannot be viewed by a third party.
Fix
There is currently no fix. I continue to pursue various technical support channels and hope to find a solution soon.
I suspect, however, that this behaviour may be by design, so that Google can offer the option to copy the event to your personal calendar.