Does relating a story about an incident that occurred with an individual who criticized mosque imams, without mentioning his name, count as backbiting and eating people's flesh?

Gheebah (backbiting) is when you mention your Muslim brother in his absence with something he would dislike if he heard it. This applies whether the person is explicitly named or alluded to, provided the listeners know who is being referred to. However, speaking about an unknown person is not considered Gheebah. The Prophet, peace be upon him, said: "What is wrong with people who said such and such?" This is unless the listener knows who is being spoken about. Gheebah is permissible in specific situations.