Copying @ARGV into a hash doesn't work because "update" has no value. You end up with:

%other_args = (
   update      => 'server',
   weitorsv015 => 'user',
   ebrine      => 'password',
   secret      => undef,
);
[download]

instead of

%other_args = (
   update   => undef,
   server   => 'weitorsv015',
   user     => 'ebrine',
   password => 'secret',
);
[download]