See: What does Autovivify mean?

Calling $list->[0] causes $list to autovivify. You can see this happening here: 

#!perl

use strict;

my $list = undef;
print ref $list, "\n"; # should print only a blank line

my $item = $list->[0];
print ref $list, "\n"; # should print ARRAY

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In reply to Re: undefined value as an ARRAY reference sometimes ok by chilledham
in thread undefined value as an ARRAY reference sometimes ok by Anonymous Monk

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