I can confirm that adding the return is fixing the URL of a node, i'll explain:
When we have the lincoln.local and the shared option is turned on we have vsite with the final address ```lincoln.local/lincoln```.
Without the return, after editing a node the address of the node will be ```http://lincoln.local/lincoln/lincoln/classes/class```
With the return the address will be ```http://lincoln.local/lincoln/classes/class```

This is caused in the ```parent::rewrite()``` which eventually generate the url ```http://lincoln.local/lincoln/lincoln/classes/class```