North Carolina owners are responsible for designating a lien agent, not GC's - so that shouldn't have any impact on the GC's mechanics lien rights. Further, since the project is residential in nature, there's a good chance no lien agent was required, anyway. Lien agents aren't required when the project is less than $30,000 or for single-family, owner-occupied residences.
For more information on North Carolina lien agents and lien rights in general:
- North Carolina and the Lien Agent- North Carolina Mechanics Lien Guide and FAQs