When Gru grabs Edith while trying to get the girls to sleep, Agnes is shown hopping on her bed while she laughs out loud, the sound of her laughter continues to play briefly even after she stops laughing.
After Gru punches the shark, and as Vector takes off, we get an aerial shot of the area and Gru is in a solid circle wall, apart from the entrance gate. The pyramid is outside of the wall, with the only way to reach it being to go through the gateway and round. Moments later, Gru runs towards it crossing the island but would have had to cross the wall before running straight up the pyramid.
When the Times Square JumboTron is scrolling its message, the lettering appears damaged as it scrolls and maintains the same damaged/inconsistent state throughout the screen width. As a JumboTron is composed of stationary lights, a burnt bulb will cause the characters to be whole/correct as they clear the burnt area. The damage should be stationary and not scroll with the letter.
When Gru is reading the story about the Three Little Kitties, he turns the pages while keeping his fingers inside of the puppets. This would be impossible because of the way the holes in the other pages line up with his fingers as he turns them.