Visible crew/equipment: In the Skype call with Celeste and Perry, you can see two people in the camera. (00:45:07)
Continuity mistake: During the school meeting Ed is standing against a green wall, between a small blue poster on the right and a big 'We love reading' poster on the left. His position keeps changing in every shot: Sometimes he's in between the posters, others covering the small one, and once very close to the big poster.
Continuity mistake: Celeste and Madeline are in the car and greet Bonnie, who's hiking. In the immediate shot of the copilot mirror's reflection Bonnie is nowhere to be seen.