When Buffy punches the demon, her fist is clean when she pulls it back, but when next we see her a couple of seconds later, her hand is dripping goo.
No psychiatrist would ever be allowed to speak to/about Buffy like her "fantasy" doctor did here, if they wanted to keep their license to practice.
When Buffy locks the cellar door, she inserts the key into the keyhole upside down (the key she uses is clearly too small to properly fit the lock).