Empty field title for multiple values text area field validation

Problem:
Empty title/label on validating multiple value text area field.

Screenshots:

Clean Drupal 7.24 installation with an Article content type and Questions (multiple values) field as Long text with Text area widget

You can see here the title is missing in validation error for Questions field.

Bug:
As you can see in the second image, the title is missing if you have multiple values. I debugged the _form_validate function where I see that it's trying to get the #title from each item of a field in $elements array. But the title is empty for those items.

Drupal 8:
Drupal 8 is using different UX for validation so this bug is not an issue for Drupal 8.