The alien security guard falls to his death (an obvious dummy is used), and disintegrates, leaving a burn residue on the beach. When the teenager runs to the spot where the body landed, the residue is gone.
An alien pushed forward by Vincent and shot with a ray gun burns up, but Vincent's body nearby also disappears.
The Narrator says "Sands Point Oregon", but it is actually Sand Point Oregon. There IS a Sands Point in New York.