Modifying PostProcess Film Slope can cause TSR to produce ghosting artefacts

When TSR is active, the scene is dark, and a foreground object is lit, modifying the Film/Slope value on a PostProcessVolume can lead to TSR ghosting.

TSR occurs prior to Tonemapping, so the issue appears to be that the slope is raising the black levels sufficiently to expose a normally imperceptible ghosting artefact.

Create a near-black dark scene with an object that is receiving light.
Modify a PostProcessVolume's Slope to 0.2.
When moving such that the lit foreground image dis-occludes the dark background, it is possible to cause TSR to ghost.