Continuity mistake: After Phoebe has her premonition about Paige at Prue's funeral, demonic bounty hunters show up to "eliminate" Belthazor. We see the funeral hall empty where seconds before Phoebe's premonition, there was a line of people waiting to give their condolences to the girls, Victor, Leo and Cole.
Plot hole: Phoebe says Piper and Prue were able to defeat Shax without the power of three and Piper's response is it was because "Prue was the strongest." Piper would have no recollection of this event as Tempus reversed time bringing Piper back from the dead in the timeline that she was shot in. The time reversal affected everyone's memory except Phoebe, Leo and Cole who were in the Underworld.