When Kathy is on the bed her head changes position between shots; in the wider shot she is looking away from the window, in the close up towards it. Simultaneously, in the wide shot the 'monster' is to the left hand side of the window but in the close up that follows, he has jumped to the right.
In long shots you can see that stuntman Gil Perkins (playing Charles) is wearing platform shoes to make him even taller.
Ruth lives in a small community where everybody knows everyone. They all know that her husband was killed by something falling from the sky. Nobody seems to remember that she had a son or wonders whatever happened to him.