Other mistake: After the transformation, Elizabeth is brought home. She lies asleep on the sofa. Who had the time to apply makeup to her? Her nails are shining, which means that someone has applied some polish on them. It is obvious that no actors (even male) will ever play without makeup; however, they should not have applied such an evident makeup to Elizabeth.
Continuity mistake: After a talk with Diana on the mothership, Lydia is left alone and then she takes a message out of her uniform. She wears a ring on her left middle finger and her nails are painted red. In the following shot we see Lydia's hands put the message into a box. The hands do not have their nails painted and wear no ring whatsoever.