Character mistake: At the end of the scene in the grocery store when Rachel collapses and people run to her aid, the camera pans out to reveal a sign that prominently reveals a sale on "Pop Tards" or possibly "Pop Taros."
Continuity mistake: When Elizabeth starts weeping, her bodysuit is torn above her left breast with a single tear. Post-credits Meliodas asks her to join him; now that torn spot is split in two - the first time the bit of fabric that separates the two spaces was already severed. (00:17:40 - 00:22:30)
Factual error: Helmuth von Moltke is addressed and referred to several times as Field Marshal. He wasn't promoted to that rank until 1871. He was a lieutenant-general during the Second Schleswig War in 1864.
Factual error: Constantine's driving licence is shown - it's a UK licence, but no. 7 where his signature should be is blank, and no. 8 where his full address should be simply says "England, United Kingdom." Both are printed onto the licence when it's issued - without that info it would never be issued in the first place. And it's not a fake, because why would he have a fake licence with his real information on it? It's just an incomplete prop.
Gortimer vs. The Mobile of Misfortune - S1-E3
Visible crew/equipment: When Stanley is riding the kart in the race, the shadow of the camera equipment is briefly visible bottom right, just before the kart starts to fall apart.