Continuity mistake: Tenaya 7 is running on the treadmill in flat sandals with tan straps, she then has flat sandals with black straps as she fights the guards.
Plot hole: Bonnie is the anchor for the other side and feels when supernatural beings die. How come she didn't know Katherine wasn't dead? Did she never think it was suspicious that she never felt Katherine's body after she died?
Suggested correction: Katherine died but didn't go to the other side. So she didn't need to go through Bonnie. She went to hell to Arcadius. Bonnie is not the anchor to hell, we don't know how going to hell works.
After everyone finally realises that Elena had been possessed by her Doppelgänger Predecessor, It is actually shown that Katherine were more or less dragged away from Bonnie before she could crossover to the Otherside. So we do have some idea as to how one ends up in Hell.
Suggested correction: Katherine was a human technically when she died.
Technically, she was supernatural because she was a doppelganger, so she should've gone through Bonnie.
And even she was a traveller.
Continuity mistake: The assassin is running across the square with the poisonous needle in his left hand in several shots. But moments later, when tackled to the ground, it is pressured from his closed right hand.
Continuity mistake: In the final showdown between the Queen and Alice, in the wide shot, you initially see the Ten of Clubs standing beside the Queen, but when it moves to close-up, he has disappeared from her side, only to run into the scene behind Jack and Duchess moments later. (02:52:45)
Other mistake: Curtis grabs Alisha's hand without activating her power. (00:16:45)