GroupService.getGroupList does not work as documented

The documentation for the Collaborator REST API for the GroupService.getGroupList command states that if no review ID is provided, a “list of all groups visible to the user” will be provided.  However, when this API command is issued with a user which has admin privileges (in fact, it has all possible privileges for a user), the result is not the entire list of all groups, but instead just the groups that the user is a member of. 

I can’t find the location at the moment, but somewhere in the Collaborator API documentation it specifically states that all groups can be viewed by calling this API command with an admin-level user, which makes sense, but that’s not the way it’s working for me. 

In the end, what I need is a way to get a list of all groups defined on the given Collaborator service.

SmartBear Support suggested that I post in the Collaborator Feature Request forum, but I don't have a Create Message button there, so I'm trying here for now.

Also I tried to label this post API, but there is no API label.

This is Collaborator 11.2 and the JSON API