Facts: There was a possible contract for the sale of an opal mine in NSW by the plaintiff (Pl) (English company) to the defendant (D) (NSW government). Negotiations concluded, and the agreement had to be translated into a legally binding contract. D made a formal offer to Pl to purchase the opal mine on all the agreed terms, open to a certain time. Pl accepted the offer by letter within the specified time in England, but after that time in NSW. D did not want to go through with the sale, and argued the contract had not been accepted in a timely manner.
Issue: What law applied to offer and acceptance (i.e. whether there has been timely acceptance of an offer) of a contract?
Held: The putative proper law of the contract applies. Here, the supposed proper law (with no express or inferred choice) would have been the lex situs, as the subject was immovable property. Therefore, the law was NSW law. The offer had not been accepted in a timely manner, and no contract had come into existence.
Principle: The putative (supposed) proper law of a contract determines whether an OFFER has validly been ACCEPTED so as to create a binding contract. It is also possible that the putative proper law can be the law chosen by the parties.