While that might be true it doesn't mean it is true in this case or most cases. From reading your code it would seem to me that the following works the same but is easier to read. Not saying yours is bad, but 99% of the time if you reach for GOTO you could probably phrase the problem differently so that it is not needed.

while ($idx_la > $i) {
    &log("I: $i IDX_LA: $idx_la\n");
    $phrase = join ' ', @$sl_ctl[$i..$idx_la];
    $rawtr  = $self->get_rawtr($phrase);
    if ($@$rawtr) {
        my $disam = $self->disambiguate($phrase,
                                        $rawtr,
                                        $i,$idx_la);
        push @tl_rtl, $disam;
        last;
    }
    $idx_la--;
    push @tl_rtl, $phrase;    
}
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