An unescorted buyer visits a property during Open House but forgets to tell the listing agent that he or she is represented by a buyer's broker. The listing agent spends several hours with the prospective buyer. Later, when an offer is presented through the buyer's broker, the listing broker claims to be the procuring cause of the sale and refuses to share any commission.

Discuss the possible outcome of the above situation. Please include any information from the TRELA or other TREC rules as part of the response.