To add to the detective work, changing to

#!/usr/bin/perl

$rec = {
    avg_outst => pct_pf...     # BAD
    pct_pfo   => ' ',
};
[download]

gives me

C:\Perl>perl -MO=Deparse testhang.pl
$rec = {'avg_outst', 'pct_pf', ' '};
testhang.pl syntax OK
[download]