[O] Why does Helm break org-contact group add?

[Tory S. Anderson]

I thoroughly enjoy Org Contact for managing my contacts. One of 
its features is the ability to enter +<tag-group> and have an 
entire group of contacts added to the To: or Cc: . Unfortunately, 
when global-helm-mode is enabled, it doesn't work; when `+<group> 
TAB` is entered, an error occurs:

Lisp error: (wrong-type-argument sequencep 65)

I'm new enough to debugging elisp that the lengthy error trail 
isn't very decipherable. Can anyone give me a hand on how to get 
the TAB working with the contact-fill?