result of ^^ is not the last evaluated expression.

The ^^ operator can't return the last evaluated expression since it could either be true or false, and would not indicate the success of the XOR. You can see this by using ^^:

    $ perl -E 'say q(A) ^^ q(B)'

    $ perl -E 'say q(0) ^^ q(B)'
    1

Author: briandfoy

pod/perlop.pod

@@ -1089,7 +1089,7 @@ cannot).  This is very useful for
 providing default values for variables.  If you actually want to test if
 at least one of C<$x> and C<$y> is defined, use S<C<defined($x // $y)>>.
 
-The C<||>, C<^^> and C<//> operators return the last value evaluated
+The C<||> and C<//> operators return the last value evaluated
 (unlike C's C<||> which returns 0 or 1).  Thus, a reasonably
 portable way to find out the home directory might be: