When Eve sees Carolyn in the Super 8 film, she freezes the projector so that it projects the one frame for several seconds. Doing this in an actual projector would cause the film to melt almost immediately from the heat of the projection bulb.
In the lock-picking scene, both the present-day Carolyn and the young Carolyn attempt to turn the cylinder in the wrong direction with the tension wrench. The cylinder must be rotated clockwise to open the lock.
When Villanelle is shot with the arrow and Eve runs to her, there is no blood on the sidewalk.