Not sure about the whole fleet.. but in the last paragraph of "halo - first strike",
tartarus asks the prophet: "and what of the incompetent, The one who lost the ascendant justice?"
To which the prophet responds: "bring him before the council. Let his fate match the magnitude of his failure."
Its relatively safe to assume that they were talking about the arbiter in that sence, as the arbiters trial and punishment seem to fit with this sentance.
The only problem with this theory is that in the entire halo 2 game.. there is no mention of the events in the book first strike, so we dont know for sure if the arbiter really is that ship commander.
Slavish Devotion To Rules Is A Sign One Has Nothing Better To Do With His Time. :P