During the clown fight in the alley, the glass with the presidential seal is concealed within a black pouch attached to Nick's pants on his left side. After the fight, it is attached to his right side.
Russian agent Dolly's cigarette jumps from hand to hand as she talks to Nick while leaving the shootout house.
When Nick and Bob are talking in the garage, Nick is moving around while his reflection in the window behind Bob is staying still.
When Bob confronts the bullies in the garage, the leader of the group is initially wearing sneakers. When he trips Bob a minute later, he is seen wearing flip flops.
When Nick and Bob visit Nick's parents, Nick's dad is sitting to Bob's right on the couch. Right after the camera shows the WWII picture on the mantle and cuts back to Bob on the couch, you can see Nick's dad's arm to Bob's left on the screen. (About 47:13 in the movie.)
A rope ladder is lowered from a helicopter. Judging by the length of the ladder, the helicopter is hovering only a couple of dozen feet overhead, yet there is no downdraft apparent on the people under it. No one's hair is even disturbed.