After Gretchen attacks Henry with her knife, he is shown having taken a hit to the face. This would be impossible as Gretchen stabbed him with her right hand standing with her back to him.

When Gretchen follows Ed who followed the half naked vomiting woman, she enters a room with a sign showing opening hours. On the lower end of this sign it reads "Keine Kunde erlaubt" in German, which translates to "No customer(s) allowed". This sentence is grammatically incorrect. In German it would either be "Kein Kunde" (singular) or "Keine Kunden" (plural), but "Keine Kunde" uses the plural "no" and the singular "customer".

When Herr König is explaining what is happening to Gretchen, he talks to her in english, which makes sense since she's American. Afterwards, he starts talking to Henry and Erik, and stays with english even though all three of them are German.