Node Reference Create with Automatic Node Title

I have 2 custom node types im generating titles for. I use a field called Street Address as the path for generating the title of the first content type. The second node type references the first via the Street Address field. When the user is creating content of the second node type, if the Street Address field does not exist as an entry in the first node type it auto-creates the first node type entry as well as the second node type entry the user is manually creating.

I use [field_street_address-title] as the path for auto-generating the title of the second node type. This works fine when the first node type entry already exists. But when the first node type is auto created, the title for neither node type entry is correct. I'm guessing I need to implement some php that would recognize the existence/non-existence of the referenced node, and use a different token when no referenced node is found. I am definitely not an advanced user, so if someone could help me out with this I would really appreciate it.