1, overestimating the moral development of a western society. A western society just has not yet evolved into such a state that one is automatically understood and appreciated as he volunteers to initiate a self criticism in some situation in which he is expected to defend himself. Mostly likely, such an untimely self criticism will be understood as admitting fault.
2, even in a traditional Chinese society, this self criticism is only a Confucian ideal. Often it isn't genuine either.