Tenants splattered paint on rental home floors. Prop mgr did not hold them accountable. Is she liable for cleanup?

Unless the agreement between you and the property manager states otherwise, this matter would likely be addressed under the laws and courts of North Carolina, which Michigan lawyers like myself are not familiar with. I suggest you pose this question to a North Carolina attorney on this site. Also examine the language of any contract between you and the property manager to see if they violated a provision.

It depends on the contract with the property management company and NC law, but I am curious how you know it was the first tenant and not the second. Was it on their move-in checklist? You may need to speak to a NC lawyer about this, but my practical advice is to have a company refinish the floors.