Continuity mistake: When Newman and the landlord look into Kramer's apartment through his peephole, the background doesn't match from when they look in and when he opens the door.
Continuity mistake: George teleports from being on the other side of the room to standing right next to Jerry after a cut. (00:02:45)
Continuity mistake: Kramer is holding his hands in front of him with a back scratcher in his left hand, and then suddenly after a cut his hands are not up and we don't see him holding a back scratcher. He proceeds to close the door with his left hand, which is now holding nothing. (00:05:25)
Audio problem: When George says "and it will be easy because the receipt is in my good friend," the S in the word "because" is partially cut off at the end, indicating two different recordings were edited together. (00:18:35)
Continuity mistake: When George is about to walk away from Jerry, he begins to close up his wallet, but in the next shot, it is fully open again. (00:18:40)
Answer: The name is Delores. He shouts that name at the end of the episode. Then in a later episode, "The Foundation", he runs into her. And he repeatedly calls her Delores.