Exactly right. Let me illustrate what is happening. Your data structure looks like (simplified):

$foo = { 'SOMETHING_01' => {'CLASS' => [ {'VALUE' => 'BUBBLE' } ] } }
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Let's do a little analysis, assuming $foo retains its value:

$bar = $foo->{SOMETHING_01};   # $bar is hash reference
$caz = %{$foo->{SOMETHING_01}; # $caz is a hash 
print $caz{'CLASS'};           # 'ARRAY(...)' - an array reference
print $caz{'CLASS'}->[0];      # 'HASH(...)' - a hash reference
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Note that when you copy a reference, you aren't copying the data -- you're making a new reference to the same data. By using the deep-copy method of the parent, you copy the data contained in the reference instead of the reference itself.