When Shota is carrying Nikolai away from the plane after the crash, Nikolai has a large amount of snow on his arms and back of his jacket. A few seconds later in the next shot, the snow is gone.
Nikolai is still wearing his flying goggles when he's on the "ice" raft and also as he's swimming towards the shoreline. As he reaches the shore, the goggles have disappeared.
At the end, when Nikolai is coming in for his landing, one plane has "NO STEP" painted in English on the leading edge of the wing.