JMS, the writer always stated that the parting was amicable. Sinclair appeared in a cameo in S2 and in the two-part episode War Without End in S3, which closed Sinclair's story arc. In real life, the cameo for S2 was recorded before the actor got hospitalized to start treatment for his symptoms which were as severe as something alike schizophrenia and the two-parter was shot when his condition was stable enough for filming again, but the side effects of his meds were not all too obvious yet, although the viewers could feel something was wrong, he had some odd blinking at some scenes.