Audio problem: When they scream at the cupcake shop, Gru sounds like he's behind the glass dome, while Lucy gives off a regular scream. But as we can see, Lucy is behind the dome, making a silly face, not Gru.
Audio problem: When Tony is telling Pepper about what happened to Rhodey, there is one shot of the side of Tony, slightly to a back angle where he is talking. His jaw does not move at all while speaking during that shot. (00:27:10)
Audio problem: The scene after The Flash regains his powers and saves Batman, we see Lois Lane running through a street. Her speech doesn't match what she says. (00:39:00)
Audio problem: When Superman falls from the sky due to being exposed to the Kryptonite, he is heard screaming but his mouth never moves or opens as this happens. (00:55:20)