ID 481785 - In specific scenarios Mpath produces an extreme colour difference in comparison to the default renderer.

Problem summary
In specific scenarios Mpath produces an extreme colour difference in comparison to the default renderer. 

Customer reported version
modo.n/a
Customer reported platform
n/a
Steps to reproduce
1) Download and open the attached scene file.
2) Press F9 to render the scene file.
3) Go to the Shader Tree and select the Render item. Change the Renderer to Default.
4) Press F9 to render the scene file again, notice the extreme colour difference between the two.
Expected behaviour
mPath's rendered result should be close to the result produced by the default renderer.
Actual behaviour
mPath's rendered result has an extreme colour difference when compared with the default renderer.
Workaround
Unknown. 
Reproduced by support
This bug has been reproduced in:
15.0v3 - Windows 10
15.0v1 - Windows 10
14.2v1 - Windows 10
14.1v1 - Windows 10
14.0v1 - Windows 10
13.2v1 - Windows 10

Earliest version tested
13.2v1 - This feature did not exist before this version.