The buyer did not commit a trespass as your realtor, acting as your agent, invited the buyer to tour your property unaccompanied. So, it is unlikely that the buyer broke any laws.

If you believe your agent acted inappropriately, you may have grounds to file a complaint with the Colorado Real Estate Commission for a breach of professional conduct. While the realtor’s actions are not strictly illegal, they could violate professional standards and expose both the agent and seller to unnecessary risks.

Real estate agents in Colorado owe fiduciary duties to their clients, including loyalty, care, and obedience to lawful instructions. By allowing the buyer to enter the property unaccompanied, the realtor may have breached their duty to act in the best interest of the seller, as this action does not adequately safeguard the your interests. This can expose you to liability risks, such as potential property damage, theft, or personal injury, which could be argued as negligence on the part of the agent if any issues arise during the unaccompanied visit.

Finally, whether your realtor's conduct was illegal, or at least inappropriate, would also depend on your contract with the buyer, your course of performance with other buyers, and your contract with your realtor. Only by reviewing all the facts can you make a determination of the legality of the conduct and your options.