A Resistance member says that cold-blooded animals are better adapted to cold weather. The opposite is true. If the Visitors where really cold-blooded, they couldn't survive in extreme cold as depicted in the movie.
When Mike boards the mothership a second time to get more information about the Visitors, he is seen with a laser weapon in its holster. However when he enters the mothership's water storage area, it disappears.
When the mother ship is approaching and we see a group from behind as they are watching it, Robin Maxwell leans in to her mother and puts an arm around her. In the reverse shot, she is hugging her mother. Then we cut back to behind them and she leans in and hugs her again. This is because there are two different actresses playing Robin during this scene. The shots of Robin from the front are of Blair Tefkin, who played Robin the entire duration of the series. The shots of her back during this scene are of Dominique Dunne, who was strangled to death by her boyfriend after a few days of shooting. Director Kenneth Johnson kept the reverse shots in her memory.
In the shuttle right after Mike escapes with Robin from the mothership, Mike loops the shuttle, and there is shot of them upside-down. Robin raises her arms, apparently to keep from falling out of her seat, but the entire time her hair rests on her shoulders as if right-side up.