Final answer:
Newt is accused of breaching his duty of accounting by mishandling the earnest money, which is a serious concern in a real estate transaction.
Step-by-step explanation:
If Newt's buyer client has accused him of mishandling the earnest money, the duty that might have potentially been breached is duty of accounting. This duty requires real estate agents to accurately handle and account for their client's funds during a real estate transaction.
If the earnest money, which is a deposit made to demonstrate the buyer's seriousness about purchasing a property, is not handled correctly by the agent, it would indeed constitute a breach of this duty.