The apocalypse is supposed to happen on June 27, yet Martha has visible steam coming out of her mouth when talking to Bartosz, indicating it's cold. However, in Eva's world the apocalypse takes place in November.
Starting at 47:40, the old and young "Unknowns" can be seen arriving 1986 to force the accident at the power plant. The older one is at the right side of the younger and both mouth scars are faced on their left side. Shortly after, the adult "Unknown" arrives alone with his scar also on his left side of the mouth. Since older/younger and adult are in different worlds, the younger and adult scars should be "mirrored". This scene gets fixed at 47:54, where the older one "switches" to the left side of the younger one, also fixing their scar's side.
(at 47:50) The whole shot is mirrored except for the lines on the road, the traffic lights and the stop sign.