During the shootout at the house in Agoura there is a brief shot of the hubcap of a silver Ford sedan being shot off. There is no silver Ford in any scenes before or after the shootout.
There is no need for the criminals to cut the Matisse painting from the frame as the frame is not fastened to the wall (it falls off the wall after the painting is removed) and the criminals carry other paintings from the house still in the frame.
Early in the episode, when people are laying on the grass, the camera does a lot of closeups of the ground, which can be seen to bounce, move, and wrinkle throughout the scene.
Early on, just after Angel sends Chapman to get food and drinks, a boom mike is seen very briefly at the top of the frame.