Continuity mistake: After Phoebe jump kicks a warlock and falls to the ground, there is a blonde woman standing next to them. In the next shot of the warlock, when Piper blows him up, the woman is gone. But all of the mortals had been frozen, so she couldn't have moved.
Continuity mistake: Near the end of the episode, in the scene at P3, Phoebe launched a jump kick at a warlock after Paige has been knocked down by a small energy ball. Everybody else in the club was frozen by Piper, but when Phoebe lands she jostles a blonde extra who moves from her pose.