Redistribution isn't allowed. I'm not so sure about modification. The license at the top says nothing about not being allowed to modify. It just prohibits all copying (including "adapting", but that's in the context of copying - so adapting that involves copying) - i.e. if I change the script for a different purpose I can't redistribute the modified /sbin/preinit - doesn't mean I can't legally say what lines I used, inserted at line X - and people aren't legally prevented from modifying it from there if they so choose.
I'll add my own comment to the bug whenever I remember what my username and password there were.