When Buffy is talking to Anya about alternate realities, Anya fails to mention her wish to Cordelia which was a wish that Buffy never came to Sunnydale. It's possible it never came to mind, but given her involvement in that situation and that it happen less than a year ago, it's hard to believe she would have forgotten about it.
There is no reason to suspect this is a goof. Anya might very well have chosen not to disclose Cordelia's wish, given the consequences.
At 26:47, when Buffy is talking to Anya about Jonathan, Anya is supposedly reading Jonathan's book "Oh Jonathan." But if you look at the pages of the book, they're blank - there's no writing there. In the next scene, when Buffy takes the book, there's writing on the pages.
At 24:31, as Willow and Buffy enter Tara's room, there is a mirror to the left of the door. It has a scarf draped over it to prevent it from reflecting things it shouldn't, but the bottom right corner is still exposed and in it you can see glimpses not only of Willow and Buffy but of the crew moving around behind the camera.