I Shot an Arrow into the Air - S1-E15
Other mistake: Corey sees a sign for Reno Nevada that is in the middle of nowhere, that can't be seen from the road in the distance. Who would see it?
I Shot an Arrow into the Air - S1-E15
Revealing mistake: Right after their friend dies and the commander talks about going into the mountains to search for any life signs, you can very briefly see Corry looking straight into the camera.
Answer: It's explained in the episode. The aliens are experimenting to see how humans react to various scenarios. This just happens to involve them using super strength.
Thanks. It's been a long time since I saw the episode so I forgot.