Fixed in VR Player v2.5.1, available here.
It appears that rotation directions are reversed when using the VR Player in conjunction with the renderer (e.g., to view video while playing back a Pro Tools session). Left is right, right is left, up is down, down is up, cat is dog, etc...
This affects both magic window operation as well as Oculus HMD monitoring, for both macOS and Windows versions of the VR Player.
Note that only renderer playback is affected. Playing back a muxed audio/video file behaves as expected.