Continuity mistake: Leah asks Moose if he brought the cutters, so he looks in his bag then hands Leah scissors. In the shots facing Leah she holds up the scissors by its handles, but in the shots facing Moose she holds up the scissors by its pointy end. (00:10:20)
Other mistake: Moose was narrating what he was writing in his second letter to Mr. Dunbar. There were 64 words, 12 more words after "P.S.", then "Love, Moose." A view of his finished letter showed it was way too short to have included everything he supposedly wrote, and the expected format did not match. (00:26:20 - 00:27:10)
Trivia: The celebrity address app lists several famous fictional characters, including Jack Torrance from "The Shining" and Tyler Durden from "Fight Club."