Misuse of format_plural()

This is wrong:

format_plural(count($failed_emails), 'The following recipient is already a member:', 'The following recipients are already members:');

should be:

if (count($failed_emails) == 1) {
  t('The following recipient is already a member:');
}
else {
  t('The following recipients are already members:');
}

The problem is that for example in Russian language when the $failed_emails == 21 or 31 .. the singular text 'The following recipient is already a member' will be displayed (translated into Russian).

for example here
http://localize.drupal.org/translate/languages/ru/translate?search=1%20i...
you can see than '1 invitation' is translated as '@count приглашение'
so the singular form does not mean that the count equals 1, it means the first type of formatting for texts with numeric values