So Libby just told Tim that Susan is an alien. Big big mistake on her part.
I don't think so. I think this follows a corollary to Heinlein/Lazarus Long
second method of lying successfully:
"Tell the exact truth and maybe all of it . . . . but tell it so unconvincingly that your listener is sure you are lying.
The corollary would state that some statements of truth are so outside the common experience as to be discounted by most listeners. Additionally, Libby is notably irritated with Susan and
drunk, so that may discount her statement as well.
On the other hand, many people, especially those opposed to Susan's activities, may take the statement at face value, based on Susan's demonstrated powers.
1: (TIME ENOUGH FOR LOVE, pg: 22; (c) Robert Heinlein, 1973; ISBN: 0-7394-1944-7)