This issue has been discussed on debian-legal two years ago: https://lists.debian.org/debian-legal/2012/09/msg00034.html
The common interpretation is indeed a warranty disclaimer and not a usage restriction. Emmanuel Bourg -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org