During the after death scene of Johnston Green, his right arm can be seen alternately extended and lying on his chest.
Hawkins is using a satellite to track New Bern's movements, but the image on his computer is shot from the ground, not from above, as it would be if it was a satellite image from space.
In the season finale, the men who come across several bodies feel for a pulse to see if they are alive, however, they are wearing thick gloves, making it impossible for them to be able to actually feel a pulse.
When the train approaches the tank it is clearly a steam engine, but the train "whistle" is clearly an air horn from a diesel engine.