There was a bug in Perl where

${%$Hash_reference}
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was equivalent to

${\%$Hash_reference}
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instead of evaluating the hash in scalar context. Apparently, 5.8.9 suffered from this bug, but 5.10.1 did not. The proper syntax is

${ ... expression that returns a hash reference ... }{ ... }
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so the following makes no sense:

${ %$Hash_reference }{ ... }
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You should have been using

${$Hash_reference}{$values[0]} = \@values;
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which is clearer when written as follows:

$Hash_reference->{$values[0]} = \@values;
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