I know that in the novel "ST The Return" by Shatner, the borg are able to lie. I was wondering if this novel is considered canon, and whether there are any other instances where they lie.
7 of 9 was never entirely honest while a Borg Drone. Ergo, the Borg have the capability to intentionally mislead. No reason to think they'd be incapable of lying.
Edit - additional response:
Novels are not canon in Star Trek. Only the TV shows and movies. The animated series is canon except where it conflicts with live-action tv or movies.
There are two occasions I can think of where the Borg have been been deceptive, one of which was a blatant lie:
- In Dark Frontier Part II the Borg Queen, "informs Seven that the Borg "allowed" Voyager to liberate her from the Collective". This implies Seven's original "escape" was actually a Borg plan - a deception.
- In Scorpion, the Borg agree to Janeway's proposal of giving Voyager safe passage in return for Voyager's assistance in their battle with Species 8472 (in part I). The Borg then, in part II, renege on their promise when Seven attempts to assimilate Voyager, implying their earlier agreement was a lie.
The first incarnation of the Borg we meet in TNG were seemingly cold and logical, So I would be surprised if they outright lied. The Borg we meet in later seasons of voyager portray them as being more emotional and controlled by an emotional queen, these Borg are more than capable of lying.
You could argue that certain traits like these were incorporated over time since cold and logical didn't work when dealing with Star Fleet.