Confirmed:

ActiveState Perl 5.6.1 on Win NT4 SP6a...

STARTING
Neighbors
  Node=ARRAY(0x1b9ee88)
  Node=ARRAY(0x1b9ef48)
SHOULD BE THE LAST THING PRINTED.
DESTROYING Node=ARRAY(0x1b9ee88)
DESTROYING Link=ARRAY(0x1b952cc)
DESTROYING Node=ARRAY(0x1b9ef48)

Crashed with...

The instruction at "0x28071ad3" referenced memory at <blah> whcih could not be read.

which is what happens when you write a program that uses a pointer wrongly in C...