/usr/lib/python2.7/dist-packages/UpdateManager/ReleaseNotesViewer.py is in update-manager 1:0.156.14.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/UpdateManager/../../../../share/pyshared/UpdateManager/ReleaseNotesViewer.py