Phoebe says very clearly that warlocks don't bleed, but in the first episode "Something Wicca This Way Comes", Jeremy was bleeding pretty profusely after the failed vanquish. As well as Brendan Rowe's warlock brother bled when he was stabbed in Season 1 Episode 18, "When Bad Warlocks Turn Good". And also Malcolm was bleeding in Season 2 Episode 3 "The Painted World".
Prue claims to have kept the warlock-killing dagger last seen in the season one episode "When bad Warlocks go good" yet, in that episode the dagger can be seen to fade away at the same time the warlock bodies disappear.
When Phoebe dismounts and remounts Eric, he is parallel with the kitchen door (like he could stand right up and walk through it). When Prue and Piper walk past, he is lying diagonally between the table and counter.
When Prue pokes Jack with the dagger and Piper unfreezes him, there is clearly a red dot of blood on his hand; however, a second or two later when he raises his hand, there is nothing.
Cell phone systems do not have a dial tone.
The object in the museum is believed to be a map to the location of the "Akashic Record". That would be odd, because the "Akashic Record" is a meta-physical 'record' not a 'physical object' that could be hidden, much less found.
When Eric and Phoebe are talking about their parents, Phoebe tells him that her mother died and that she never met her father. But she met their father in the beginning of season 01. Although, she speaks as though he has left and they never had contact with him.
This is incorrect. Phoebe says her dad wasn't around and that she never got the chance to know him, not that she never met him. Even though she saw him in the first season, she still doesn't know him like she would if he was around when she was growing up.
Piper froze Dan while he was outside the door when the door was shut but you could see him moving through the window.
When Phoebe crouches down onto Eric while he is frozen, her knee is directly on his elbow, illustrating the effect used to illustrate Piper's freezing power.
Dan has a thought that someday he's going to make it through the front door (of the Halliwell house.) However, Piper had invited him in earlier in the episode to prick him to see if he was a warlock. He also came in and had a talk with Manny (Prue as a man) earlier in the season.
When Prue and Piper return home from Bucklands, Prue shouts: "Jack's not a warlock!" to Phoebe, who is standing mere feet away in the hall with Eric. All four then walk out of the front door together. In the next scene, Eric acts like he's never heard the word 'warlock' before, but Prue had just shouted it right in front of him.