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.
The Slicer - S9-E7
Continuity mistake: When Elaine is woken up by her neighbor's alarm she looks at her own bedside alarm clock and it shows 3.30 AM. In the next shot when she buries her face in her pillow and screams, that clock shows 3.29 AM. (00:00:50)
Continuity mistake: When George is at the window making a complaint, a cut reveals several inconsistencies. The man at the window has his arms in a higher position in the second shot (plus his facial expression is changed), the woman no longer has her hand up on the wall, and George's left hand is suddenly resting on the table. (00:15:55)
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)
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: 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.