Just because Linux and Unix have some of the same lines of code, does NOT mean that linux copied the code from unix.
The code could have come from BSD for example and in fact there are several instances where linux and Unix share (or shared) the same BSD code.
The code could also have come from implementing the Posix Standard. The PDF linked to seems to be an implementation of errno.h which I believe is part of the POSIX standard.
So again just because the code appears in Unix, does NOT mean that Unix had copyright ownership of that code.
To prove its case SCO would have had to prove that:
a) Linux had lines of code that were substantially similar to Unix. (some minor examples provided but even that was not definitive)
In fact the judge who supervised the discovery kept asking for details and at the end of the multi year discovery process, said, "Is this all you've got?"
b) Unix had copyrights to the code in question (again not proven)
c) SCO owned the Unix copyrights (again not proven)
d) SCO never granted the rights to use that code in any way. In fact Caldera (aka SCO) distributed a version of Linux under the GPL which in effect granted GPL license to any of their code that happened to be in Linux.
So even if all of a, b, and c were true,
they STILL did not have a case for infringement.
I almost wish that SCO had owned the UNIX copyrights, because then this whole issue would have been resolved by now, instead of relying on Novell.