Thomas A. Carella filed for Chapter 7 bankruptcy. At the time, HSBC Bank USA held the sum of $16,540.94 on deposit in a joint bank account in the names of Carella and his father, Thomas J. Carella. The son sought to protect the money in the bank account, arguing that it was his father's account. The father had set up the joint account after finding out he needed to undergo heart bypass surgery. The father argues that he set up the joint account for convenience so that his son would have access to the money should the father pass away. The father survived the surgery and continued to manage the joint account. Only the father deposited or withdrew money from the account at any time. The son's bankruptcy trustee argued that the account was a gift causa mortis and thus is available as part of the bankruptcy. Did the joint account constitute a gift causa mortis? What are the necessary elements for establishing the joint account as a gift causa mortis?