The (or at least a) problem as I saw it is that as written:

$key eq "year"
  ?
   &show($bros->{$data}->[$list])
  :
   $index = 0;
   while($bros->{$ydx[$list]}->[$index]->{$key} !~ $data/i){
        $index++;
        }
        $yr = $ydx[$list];
        &show($bros->{$ydx[$list]}->[$index]);
[download]

the indentation is hiding what's happening. When written:

$key eq "year" ? &show($bros->{$data}->[$list]) : $index = 0;
while($bros->{$ydx[$list]}->[$index]->{$key} !~ /$data/i){
    $index++;
}
$yr = $ydx[$list];
&show($bros->{$ydx[$list]}->[$index]);
[download]

it is much more obvious that the while loop and two following statements are executed no matter what value $key holds.