Continuity mistake: After Max takes a bite of the tomato, the stain on his shirt decreases significantly after just a few shots. (00:18:05)
Continuity mistake: The morning after Max sleeps with Fanny, after she sits on the bed after trying to creep out of the room, a strand of hair is over her eye. The shot cuts to Max, but when the shot cuts back to Fanny, the strand of hair is no longer over her eye without it being touched.
Continuity mistake: After Russell Crowe agrees with Didier to clean up the house and pool, a couple of scenes later they are cleaning the pool which is empty, but the pool was filled a day earlier by Marion when Russell was stuck in the pool. The items in the pool are dry, not wet as they would be if the pool was recently drained. (00:47:45 - 00:49:00)
Continuity mistake: Exterior shots of Max's office building show a round tapered building with triangular windows and a circular floor cross section. Interior shots show a standard rectangular building with square windows.
Continuity mistake: The scene of the dinner at Monsieur Duflot's home, was evening. The scene in the kitchen, when Monsieur Duflot told his wife that Max has arrived, you can see through the door daylight. When Max went outside, it was evening again.
Answer: I think the Van Gogh is really part of his buy-out package from the brokerage. This is the copy which was hanging on the boss' wall, but not the original which the boss kept in the vault.