In the end, Matthew is hiding in the dark, and we see a pod person shining a flashlight around his hiding place. The flashlight gets aimed at the camera, washing it out with white, and then the film cuts to Matthew walking through town the next day. We later learn that he has been assimilated, so that part where the flashlight hits the camera lens is Matthew getting discovered.
That shot is also a clever play on a ubiquitous piece of film grammar. Usually, the shot of the flashlight would be followed by a shot of the spot where Matthew had been a second before. It's such a cliché that audiences will assume that's what happened without the film actually showing he's not there! The twist relies on the audience filling in the blanks mentally based on how they know movies work, then revealing that they assumed wrong.
Kibner wears a leather carpal tunnel brace on his hand. Earlier in the film, Jack complains that Kibner publishes a book every six months. Kibner writes books so quickly, no wonder he's got carpal tunnel syndrome!
While it's uncertain whether anyone had any time to think about this, it would likely have had a nasty effect on the temporary survivors who had brought home the pod flowers when/if they realized they'd accidentally killed their loved ones with what they thought was a pretty gift.
