When Reached and Duffy are talking in the alleyway whenever the camera is on Duffy's face there is a strong wind blowing her hair back, but when the camera is behind her there is no wind at all and her hair lies flat.
When Neagley puts her mug in the microwave she sets the time for 1:00 which will only result in a lukewarm cup of chocolate.
In a scene where Quinn is preparing a revolver for Russian Roulette, he puts one bullet in the cylinder and spins it several times before closing the cylinder, viewers hear the expected click-click-click of a spinning cylinder. An open cylinder spins freely and silently.