In "The Rescue", the alien "priest" tells Charles he may kiss the bride (Diana). In this episode, Willie introduces Thelma to the concept of a human custom: kissing.
In the final scene, Julie says that Kyle has stowed away aboard the Leader's shuttle. But there was a crowd of people all watching as Elizabeth boarded the shuttle and then the door closed, so he couldn't have done so without being seen.
When Donovan, Phillip, Elizabeth and Willie are going to the Nuclear Fusion reactor to disable it, a front view shows Willie putting a cloak on the shoulders of Elizabeth, a brief glimpse of the boom mic moves on the upper left out of view.