Errors when deny new autocomplete terms used with field collections

Issue Summary

First off, forgive me if I'm doing things wrong here, this is my first post as well as my first patch.

Steps to reproduce:
Download and enable latest of each content taxonomy (7.x-1.x-dev | Jun, 22) and field collection (7.x-1.0-beta2 | Aug, 18)
Create a content type with a field collection
Create a sample vocabulary and add a few sample terms
Add a term reference field with a tagging widget
Click "Deny any new terms" in the field settings
Create new content with a term other than one previously created

Expected results:
Content creation to be halted and returned to form with an error message denying the addition.

Actual results:
Content is added with new term and PHP errors displayed (okay, notice and warning, but you knew what I meant!)

Notice: Undefined index: field_ing_unit in content_taxonomy_autocomplete_validate_deny_new_terms() (line 125 of /Users/admin/Documents/workspace/drupal7.modules-contrib/trunk/content_taxonomy/content_taxonomy_autocomplete.module).
Warning: Invalid argument supplied for foreach() in content_taxonomy_autocomplete_validate_deny_new_terms() (line 125 of /Users/admin/Documents/workspace/drupal7.modules-contrib/trunk/content_taxonomy/content_taxonomy_autocomplete.module).

Explanation:
This is a result of the way field collections (and possibly other special special fields?) are structured within $form_state. The actual fields are not immediate children of the '#values' but are within their respective field collection (possibly even a few levels deep if you're like me. However, content_taxonomy_autocomplete_validate_deny_new_terms is assuming that all the fields are immediate children.

Solution:
If the element var has parents, then we drill into the $form_state for the actual element before checking whether the tid is to be created or not. Perhaps there is a better way to do this than iteratively drilling down into the array, if so I would love to see it.