During the silicates' attack on the main building, the townspeople flee into a back room. However, several are trapped outside in the hall and scream to be let in. Seconds later, a silicate tentacle smashes through a door panel, implying those people screaming to be let in were killed. Yet, later, when the people in the room open the doors to see the silicates dead, not one single corpse is present.
Dr. Phillip's dog is hit by a strong dose of Strontium-90. Later, strontium 90 is taken from Phillips' reactor to dose the cattle. In 1966, the nuclear reactors capable of producing Strontium-90 were far larger than the one in Phillips' lab and needed giant control boards, as well as huge amounts of water for cooling, none of which were in evidence.