The attached project implements planar reflections by mirroring a camera across a reflection plane (plane at y=0, normal=y).

How to reproduce:

Incorrect Multipass Shadows:
1) Open the attached project and enable Oculus or OpenVR SDKs.
2) Set Stereo Rendering Method to Multipass.
3) Enable the directional light, play, and notice that the shadows of the reflected objects below the plane are incorrect.
4) Enable the point light and disable the directional light. The shadows cast by the point light should appear correct on the reflected objects below the plane.

Incorrect Singlepass Reflections:
1) Open the attached project and enable Oculus or OpenVR SDKs.
2) Set Stereo Rendering Method to Singlepass.
3) Enter playmode. The reflected objects below the plane will appear to be incorrectly scaled and translated.

Results:

Multipass:
Expected Results: The cubes, lighting, and shadows should correctly be reproduced by the reflected camera.
Actual Results: Realtime directional shadows are incorrect in the right eye while point light shadows remain correct in both eyes.

Singlepass:
Expected Results: The cubes, lighting, and shadows should correctly be reproduced by the reflected camera.
Actual Results:
-Entire output from the reflected camera is incorrect.
-It appears to be scaled along the HMD's horizontal axis.
-The edge of the right eye's occlusion mesh is visible in the left eye.

Reproducible in all version of Unity (5.6).
Note: Behavior is correct in 2D.