What are the principles of fiduciary conduct in real estate agent law?

In D’Atri v. Chilcott, supra, Galligan J. at para 32 stated: I think therefore that it is clear from the authorities that the following principles are applicable to this case: 1. That the relationship between a real estate agent and the person who has retained him to sell his property is a fiduciary and confidential one; 2. that there is a duty upon such an agent to make full disclosure of all facts within the knowledge of the agent which might affect the value of the property; 3. that not only must the price paid be adequate but the transaction must be a righteous one and the price obtained must be as advantageous to the principal as any other price that the agent could, by the exercise of diligence on his principal’s behalf, have obtained from a third person, and 4. that the onus is upon the agent to prove that those duties have been fully complied with.