In the bar, Prue transfers cream from the creamer magically without the cream being poured into her cup which is not the way her powers worked throughout the series. If the cream left the creamer, it would be seen traveling to the cup and not just appearing in it.
When Roger tells Prue about the promotion he got, his green pen changes to the black pen that squirts ink.
Prue is seen picking up a newspaper and we see part of the headline which has a photo next to it. As the scene progresses and different shots were used, the paper switches back and forth from the headline with a photo to the other side of the folded newspaper.
Piper closes the box after she hands Jeremy his fortune cookie but in the next shot, it's still open.
Phoebe's flashlight beam is seen lighting the attic when the attic door first opens. When the camera goes back to Phoebe the flashlight is at her side, facing down.
Contrary to myth, no witches were burned at the stake in the USA. In Salem, MA, there were witches that were hung, but none were burned. One was crushed by stones.
The establishing shot of the Manor (the Halliwell house) shows Piper going in the door with a black umbrella with a white stripe around the outer edge. The next shot, from the interior, shows her hanging up a black umbrella with a floral print. This happened because the establishing shot comes from the original, unaired pilot but the interior scene was re-shot.
When Piper freezes Jeremy the elevator freezes as well but it remains stationary when Jeremy unfreezes.
When Phoebe looks in the mirror, Alyssa Milano's tattoo is visible which was covered up by make-up the first season.
As a chef, Piper would not have worn nail polish for her audition. She should have worn gloves and a hair net.
When Piper freezes Jeremy in the moving elevator, the elevator stops and allows her the opportunity to escape. When her powers wear off and Jeremy unfreezes, the elevator remains still, even though it should have resumed moving.
Right after the sisters finished the spell to stop Jeremy, Prue & Piper picked up the candles. When Phoebe's premonition showed Jeremy was still alive they all ran very quickly down the stairs (candles in hand) - then the camera angle switched to a view at the bottom of the stairs and the girls came running down carrying no candles.
After Piper accidentally freezes Chef Moore and she goes to fill the baster with the port, we hear the sound of the baster being filled, but Piper never squeezes the bulb.
It is stated several times that Piper can freeze time, although in reality she can only freeze her surroundings.
In the beginning, after the witch is killed, Kit the cat is seen in her home and appears to be hers. However, there was never any explanation as to how or why Kit was with her or what her connection to the Charmed ones was.