Discuss the rights and liabilities of all parties.

Nino Calabrese is an art broker based in Melbourne. For a commission ("introduction fee") he organizes the sale and purchase of artwork for his various clients. He often attends art auctions where he purchases art on the specific instructions of his clients. On 1 June of 2021 he attended the prestigious Bonhams Melbourne Art auction, which he had visited and purchased artworks for several years. He was well known by the staff and auctioneers of Bonhams Artworks Pty Ltd who hold the auctions. Since he was a regular customer Bonhams organised a credit account whereby he could purchase an artwork in his own name or on behalf of his clients. The terms of the credit account includedinter aliathe following terms:

Clause 13: Full purchase monies of artwork as defined in the sales contracts to be provided in full within 45 calendar days of the date of the contract of sale.

At the 2021 Bonhams Melbourne Art auction Nino noticed the very rareThe Last Supperby Vermeer. What caught Nino's attention was that it was being described by the auctioneer as a copy, and the reserve price was only $150,000. Nino thought it was the original, not a copy, and thus worth $1,000,000. One of Nino's regular clients, Oliver, had expressed interest in the painting some months ago. Nino had purchased many paintings for Oliver in the past so he tried to contact Oliver to see if he was still interested. However, Nino was unable to contact him. After a moment's thought, Nino decided to purchase the painting for Oliver, assuming that with Oliver's wealth and the mistake made by the auctioneer, that Oliver would be thrilled to purchase the painting. After some heated bidding Nino managed to purchase the painting for $250,000. Nino, then signed the contract of sale on behalf of Oliver for $250,000. The auctioneer who knew Oliver and Nino quite well commented: "Well, I hope Oliver is happy with this one." Nino smiled.

The next day (2 June) Nino spoke to Oliver and told him about the purchase ofThe LastSupper. Oliver simply replied: "Well old chum, kudos for thinking of me, but I'd rather not. Finances are lacking at the moment." Nino replied that Oliver's response was disappointing, Oliver said: "Should have checked first old boy, should have checked first."

Nino told his employee/assistant Lisa: "Find a purchaser in the next 45 days!" Lisa was also under an express instruction to obtain a price of $1,000,000. On 12 July, Lisa approached Preston Galleries and, without mentioning Nino, contracted to sellThe Last Supperfor $1.3 million. Lisa intended to keep the profit ($300,000) from thistransaction for herself. On 16 July, Bonhams Melbourne Art discovered what Lisa was trying to do, and told Nino that it intended to withdraw from the contract and keepThe Last Supper.

On 17 July, Oliver rang Nino and told Nino he had changed his mind and purported to ratify the purchase ofThe Last Supperfrom Bonhams of 1 June 2021. Oliver justified the change of mind by saying: "You never told me it was an original old boy!"