Other mistake: When Agnes screams after the evil minion tries to eat her unicorn, the noise shatters glass items and a sculpture on the mantelpiece as well as the evil minion's goggles. But Margo's glasses do not appear shattered at all.
Other mistake: As Eduardo goes to leave the cupcake shop, Gru believes he could be El Macho and Eduardo leaves. Gru tells Lucy about El Macho for about 90 seconds, then Eduardo is seen from outside the cake shop window only just about to go up the escalator, when the distance between the shop and escalator is only a few meters. (00:27:55 - 00:29:25)