When Giles is talking to Mrs. Post in the library office about the glove she had taken her sweater off, but when she says to hide the glove the camera shows her wearing the sweater again. Once the camera changes again she is no longer wearing the sweater.
When Faith finds Lagos in the cemetery, the "stone" crypt in which the demon is rummaging wobbles, revealing it to be made of either foam or light wood.
At 36:14, as Buffy says, "Faith, we can figure this out," you can see the tip of the boom microphone dipping into the top of the frame.
One should think Giles would be a lot more forgiving about Buffy not telling him about Angel's return, seeing as how in the past, Giles himself almost got the whole gang killed specifically by being too embarrassed to tell them about his own dangerous and foolhardy youth spent in a demon-worshiping magical cult.