Zara is a local GP (doctor) in Canberra. She has an elderly patient named Archibald who has attended the surgery for medical attention for the past 15 years. Archibald does not have any family in Canberra. Over the years Zara has provided further support (E.g. dropping off meals when he is unwell and driving him to run errands on the weekend). Archibald is grateful to Zara and decides to gift her $100,000 and gets his lawyer to draw up a simple contract to transfer $100,000 to Zara in exchange for her promising to provide ongoing support. 

The lawyer explains the consequences of the contract to Archibald. Zara tells Archibald ‘this isn’t necessary, of course I’m happy to assist you for free’. Nevertheless, both sign and Zara puts the money in her savings account. Zara continues to support Archibald until his death later that year. After his death, his son (the beneficiary under his will) seeks to get the $100,000 back.

Is it likely that Zara will be able to keep the $100,000? What relevant factors would the court consider when making its decision?