thats not quite what I have read, but very close. I read that the mandalorings, Ulic sith forces, and the krath forces attack Coursant and in the middle of the battle the Krath retreat for unkown reasons. And Mandalor keeps on fighting with Uilc. Then he either sees Uilc taken away, or Uilc uses the force to tell him. They retreat to Yavin and tell Exar of the tresion. They both go and rescue Uilc and the sith kill there masters if it is possible (this is were we get that tradition). One of exar stronger appratainces feils to kill his master and is told to retrive and amulet used by Naga Shadow. And then Him and Aleen use it to destory the jedi libray. But exar and ulic new they would die for both of there failers.
So it was preety much the same just little difffernt