There were few things in the world that Saleen was able to rely on, and he knew that very well, unless he was willing to give up what he was and what he had. Nailisi and the Winged Skull had taken Saleen to be their backup, paying the price by giving up their freedom.
His teacher was hardly considered his backup. Despite Jason being very good to Saleen, Jason had done everything he could have done for him, so much so that Jason was willing to do things that were unbefitting of his position as Saleen's teacher.
There was no way, however, that Saleen could have always taken Jason to be his backup. Jason was capable of advancing at a frightening rate. It was only a matter of time before Jason left Myers Mainland for good. No one knew which crystal wall systems Jason would end up in. Suffice to say that there was no way Saleen could have continued to be by his side by then.