[1] Skeptical investigator Paul Heuzé and a professional illusionist known as Professor Dicksonn suspected that Guzyk was fraudulent and that Geley and other psychical researchers had been duped by trickery.

[1] In November 1923, Heuzé organized five scientists, including French physicist Paul Langevin to observe Guzyk during a series of séances at Sorbonne.

"[3] Price also noted that Guzyk impersonated a "spirit" animal during a séance by placing his hand in a stocking to stimulate the illusion of a snapping jaw.

[4] Psychologist Max Dessoir wrote that the trick of Guzyk was to use his "foot for psychic touches and sounds".

[10] The psychical researcher Paul Tabori has written that it was established beyond doubt that Guzyk had cheated at his séances.