Continuity mistake: When Gru is making balloons with his balloon gun thing he attaches an inflated unicorn balloon to the door frame and an exterior shot of the front lawn is shown. This shot shows a playhouse on the right hand side of the lawn. Later on, when Lucy arrives at the house, the playhouse is no longer on the lawn. (00:03:30 - 00:07:45)
Continuity mistake: When the elevator door opens to show El Macho's lair, Gru walks out and there is no-one in sight. A few shots later, El Macho has suddenly appeared behind Gru. There was no space behind Gru that El Macho could have hid behind. (01:06:00)
Plot hole: When Gru and Lucy are searching Eduardo's restaurant, Eduardo's pet chicken begins a fight with Gru and Lucy which involves a lot of screaming, breaking tables, the chicken battering Gru which was all very loud, yet Eduardo only finds out someone was in the restaurant as soon as he walks up to the door, despite all the noise from the fight between Gru, Lucy and the chicken. (00:34:20 - 00:36:10)
Continuity mistake: In the opening scene at the Arctic Circle, two of the workers are shown playing poker. The player on the right pushes the coin pile to the left side of the container. A couple of shots later, after the player on the left has claimed victory, the coin pile has suddenly moved to the middle. (00:01:35)
Other mistake: After Gru has left El Macho's lair, Gru goes to get the girls and finds Margo sitting at a table eating from a nacho hat that has guacamole in it. The hat is slanted sideways, but the guacamole remains in fixed position and never slides to the side. (01:09:20)
Continuity mistake: At the mall the double escalator in front of "Eagle Hair Club" appears and disappears several times between shots and scenes. (00:24:55 - 00:41:05)
Chosen answer: The car is always shown in shots from the front so we can't see if the boot had a leak.
boss of epicness
If the boot had a leak large enough to admit the starfish it would have filled with water and Gru would have drowned.