M3gan reads Cady Alice's Adventures in Wonderland, however; the line of Tweedledee's M3gan reads is from Through the Looking-Glass, and What Alice Found There.
The teacher sends her pupils to the woods to collect chestnuts. Later we learn that the date when all this happened is May 30th. Chestnuts ripen in autumn, around September-October.
At about 1:00:00, M3gan shoots Celia with a nail gun, but nail guns have a safety devices that prevents them from being fired without being against a solid object.
Right after Cady is bitten by the neighbor's dog Dewey Megan glares at Cecelia over the fence. Megan is not tall enough to look over the fence.
At 00:37, When M3gan grabs the dog through the hole in the fence, the face of the person is not M3gan.
M3gan references Cady's parents dying in a crash on I-84 'outside of Oregon,' which doesn't make sense as Oregon is a state. Someone would either say 'outside of' a city, a different state.