The shot of the helicopter flying over downtown LA with Sikes and Francisco is reversed. The words "City National Bank" on the skyscraper and the helicopter's registration number (N32PM) are clearly backwards.
In the previous film, Alien Nation: Dark Horizon, Matt and Cathy decide to form a relationship. This film shows the two exploring intimacy for the first time, despite the opening narration establishing that this film takes place two years later.
A boom mic is visible when Susan is trying to feed the child in the Francisco house.