Is this the conduct of a 'sly and unpredictable villain'?
Decidedly so, if the villain, for the purposes of his joke, thinks to simulate the altruist.
Then how will you know villain from altruist?
Cugel shrugged. It is not an important distinction.

Chapter 3, section 2, "Faucelme" - Quotations and text from the Dying Earth novels - Cugel's Saga (1983)