SceneObjectsOnly validator shows error if viewing prefab via Project Window

[timbo-tj]

Describe the bug
When viewed in the Inspector (without opening up the Prefab), the 'SceneObjectsOnly' validator shows an error if the root objct has any scripts that have fields that reference any of its children. The error disappears if you open the prefab and select it in the hierarchy

Expected behavior
No error. References to objects without its own hierarchy should not result in an error.

Code Sample

    [SerializeField, Required, SceneObjectsOnly] private FlowSystem _flowSystem;

Screenshots

Desktop: Windows
Unity version: 6.3 LTS
Tri Inspector version: 1.15.1