When Buffy is out shopping for her dress and Pike is on his bike beside her, they stop to talk and have an argument. Buffy walks off and Pike turns his bike around to drive off, but as he does this, his bike suddenly moves a few feet away from the wall he was right next to in the previous shot.
In chapter 18 of the DVD when Buffy is cheering at the basketball game and Grueller (now a vampire) shows up we see him growling at a player from the other team. The player then tells him "Here, take it" and hands him the ball. The player from the other team (in the red) is Ben Affleck, pre-stardom.