Deliberate mistake: At the end when Ali smokes the huge spliff, look in the difference in length between when he first lights it and starts smoking it and when he starts blowing the smoke out. It's about 10 times smaller in the second shot.
Continuity mistake: The remote control of the hi-fi teleports between shots when Kate visits Ali at home. Ali leaves it next to the wall (along with the other remote), but it's not there anymore when Kate gets the remote of the telly some shots later.
Continuity mistake: In the scene where Ali is at the center with the kids, he gives some yellow stickers to one of them and the kid sticks them to his arm. But in the next few shots the stickers keep changing their position on the kid's arm.
