When Buffy and Angel are kissing on his bed there is lighting from what appears to be a window with rain running down pane. Then lightning flashes through the same window. Why would a vampire's apartment have a window which light could shine through?
Willow explains that "Round Robin" is when everybody calls everybody else's mom, yet when Xander starts, he calls his own mother.
When Buffy and Angel are escaping through the manhole, the supposedly heavy concrete cap shifts as both characters brush against it while climbing the ladder out.
When Angel and Buffy are running away from the Judge, they jump down the hole in the room. Drusilla points and mouths "Go" to the other vampires, but Spike's voice is heard.
Buffy makes a grievous error while discussing her dream about Drusilla. She comments that Dru could be alive since a body was never found. As the Slayer, Buffy knows that Dru couldn't be alive if there's no body, since vampires turn to dust when slain.
When Buffy awakes from her nightmare from falling asleep on the desk, you see she is wearing the Claddagh ring on her left ring finger with the heart tip pointed down. Wearing the ring this way would symbolize that she and Angel are married. She should be wearing the ring on her right ring finger.