ID 266825 - Viewer downrez sizes show different alphas from Hybrid Core output from Primatte

Problem summary
Viewer downrez sizes show different alphas from Hybrid Core output from Primatte 

Customer reported version
nuke.10.5v1

Customer reported platform
windows7

Steps to reproduce

1)  Launch Nuke in safe mode, and open the attached script

2)  click in the Viewer and hit 'a' to display the alpha

3)  switch Viewer downrez control through 1:1, 1:2, 1:4, 1:8, 1:16, 1:32 and note different alphas

Workaround
Unknown.

Reproduced by support
OS 10.10.5
Nuke10.5v1, 10.5v2

Expected behaviour
same alpha

Actual behaviour
different alphas