When John is milking the cow, Lee pushes it, knocking the Thermos from John's hand. It falls upside down, but in the next shot it is right side up.
(at around 30 mins) Lee and Jack wake up in the middle of a field full of cows. One cow puts her head into the car and wakes them. They decide to milk the cow for breakfast. The cow's head remains inside the car while being milked. Lee is at the back end of the cow, while Jack is sitting on the car's running board with both hands busy milking the cow. At this point, the cow is inside the car chewing a hat. Then a mysterious hand appears under the cow's jaw holding the cow in place. When the view returns to Lee and Jack, it's apparent it wasn't either one of them.
The street sign on the corner of the shop where Lee tries to pawn the stolen bracelet reads "3rd Avenue" and "West 54th Street" in NYC. With 3rd Avenue being east of Fifth Avenue, which divides east from west Manhattan, the street sign should read "East 54th Street."