Plot hole: According to the family tree viewed in this episode, Penny "Grams" Halliwell was born on 6/23/1937, and her daughter Patty, the Charmed Ones' mother, was born on 4/5/1950. In addition, Patty's father was born in 1930. So, according to this, Penny gave birth to her daughter at age 12, while married to a 20 year old man. That's quite outlandish, to say the least. (00:20:05)
Plot hole: It is stated Leo is born on May 6th, 1924. Yet he was in his 20's as Piper's ex-lover in his past life around 1924. It also stated that that is when he died and became a whitelighter but the war wasn't until 1942. He died shortly after that meaning he didn't become a whitelighter until after 1942.
Be Careful What You Witch For - S2-E22
Plot hole: When teenage Prue has run away with the demon, and Phoebe and Piper find her in the park, teenage Prue is 'killed'. Her sisters drive her home to get Leo to heal her, but shouldn't they have just been able to call to Leo to orb to them when Prue was first hurt, and heal her in the park, and save driving back to the Manor, risking Prue dying?
Suggested correction: I see orbing to the park but he didn't heal her, she was already dead and he can't heal the dead, that's why the genie brought her back - that's what Phoebe wished for.
But if they would have called for him right away - he would have been able to heal her before she died. However at this point in time I don't think they knew how to call for him.