During the fight scene in The Bronze, when Buffy frees herself from her ropes she starts to untie Cordelia and loosens the ropes on her left hand significantly, loose enough for Cordelia to remove her hand. At the end of the scene, the ropes are tight again.
At 35:12 just after Buffy passes out, screen fades to black, then an establishing shot appears of the exterior of the Bronze with a sign that says "Closed for fumigation". It's the same shot used in the episode 7 "Angel".
At 40:40, when Buffy is focusing to hear Cordelia, her hair majestically blows in a breeze...despite being indoors with no air flow.
Just before Harmony falls down the stairs, she has a purple backpack slung over her right shoulder, but it is gone when she tumbles down the steps. Apparently, Harmony's backpack gets flung to the floor at the top of the landing before she starts her tumble down. It can be clearly seen at 33:28 on the landing as if "the ghost" grabbed it away while pushing Harmony.
When Mitch is getting dressed in the locker room, he pulls his jeans on under the towel. When the angle changes, the towel is gone. Even though they don't show him doing it, the towel has dropped to the floor and can be seen under the bench in this shot. Had the close up showed him with the towel back around his waist it would then be a continuity error.
At 00:34, Cordelia states "My eyes are hazel, Hellen Keller". In reality, Charisma Carpenter's eyes are actually dark brown. This is not a GOOF. There are many social media sites where Charisma Carpenter identifies her eye color as HAZEL, since she is the expert of her own eye color, it's HAZEL. Which by the way is most often described as brown with flecks of green.
At 38:10 when Xander blacks out and falls over, his head hits Willow's face and she momentarily breaks character with a faint smile. There is no way to determine that Alyson Hannigan has broken character. The camera is too far from the actors faces to make such a determination. Willow's is losing conscious as her head was jarred with Xander passing-out and bumped her head with his so of course there would be some movement of Willow's face/head with the bump.
(Around 18:45) When Cordelia is about to give her speech, the camera pans down from a distance. As it pans down, you can see the screen shake for a second.
Buffy says, "*We* did this to her," in regards to Marcie turning invisible due to people not noticing her, but she is stated to have been missing for six months, and Buffy has only recently transferred to Sunnydale High School and would not have met Marcie before she turned invisible.