Revealing mistake: At the river to cross over to Mt Weather, the vine used to swing across the river is just a standard rope, camouflaged. You can see it best when Finn recovers it after Jasper has jumped.
The 100 (2014)
1 revealing mistake in Pilot - chronological order
Starring: Eliza Taylor, Paige Turco, Marie Avgeropoulos, Thomas McDonell
Continuity mistake: At the beginning of the episode as Clarke is walking towards the window in the door, her right arm is already injured, but she doesn't actually get that injury until she breaks the window and reaches through the glass, which cuts her right arm.
Earth Skills - S1-E2
Clarke: Follow me.
Bellamy: And why would I do that?
Clarke: Because you want them to follow you. And right now they're thinking only one of us is scared.