Damien Calaque of the Louis Pasteur University, Strasbourg, criticized Grichka Bogdanov's unpublished preprint "Construction of cocycle bicrossproducts by twisting". In Calaque's estimation, the results presented in the preprint did not have sufficient novelty and interest to merit an independent journal article, and moreover the principal theorem was, in its current formulation, false: Grichka Bogdanov's construction yields a bialgebra which is not necessarily a Hopf algebra, the latter being a type of mathematical object which must satisfy additional conditions.