When Stacie (Jessica Biel) is carrying in her groceries the baguette in the bag disappears, then reappears in the next shot.
The Alfa Romeo that the star, Gerard Butler, drives has two different type of wheels on the car. In the beginning and the end, they are the same. In the middle the car has different wheels.
When George gets out of the Ferrari in front of his house, his landlord, Param, walks towards him. And asks him for the money George owes him. George takes the envelope out of the glovebox of the Ferrari. He pays Param the money, and walks to the front door of the house. But he doesn't have the envelope anymore in his hands, neither he put the envelope back in the glovebox.
At the end of the movie, when George returns there is a soccer ball on the grass. They then start playing soccer with a different soccer ball moments later.
Dave gives George an envelope full of cash while they're at the soccer pitch, and presumably George drives home with it (in his Alfa Romeo). The next time we see that envelope (still filled with cash), it's in the glove compartment of Dave's Ferrari, on a different day.
When Lewis shows a picture he has drawn of himself and his parents, his father is wearing a Celtic shirt with green and white vertical stripes. However, Celtic's shirts have horizontal stripes and Lewis would know this: he has a framed Celtic shirt on his wall, seen mere seconds before.
when George tell he wore the red colored Adidas-made Liverpool jersey during 2005 European cup final, actually that jersey was 1995/96 season home kit. During 2004/05 season Liverpool football attire made by Reebok.
When George drives home in Dave's Ferrari, Param corners him about his unpaid rent. George whips out the envelope stuffed with cash, counts out what he thinks is $900 (actually it's $1000), and hands the money to Param, leaving some money still in his (George's) hand. Other than Param returning the extra $100 later that night, we never see nor hear about the rest of that money.