Results are given in Yang, Jiang and Cocquempot (Yang, H., Jiang, B., and Cocquempot, V. (2009), ‘Fault Tolerance Analysis for Stochastic Systems using Switching Diffusion Processes’, International Journal of Control, 82, 1516–1525) regarding the overall stability of switched diffusion processes based on stability properties of separate processes combined through stochastic switching. This article argues two main results to be empty, in that the presented hypotheses are logically inconsistent.