Even though Garak's actions in this episode were the result of poisoning by a drug, isn't he still responsible for what he did? O'Brien did say that there would be a hearing about it afterwards but also that "the truth would come out". But is the truth relevant, in this case?
The natural reaction would, of course, be to say that Garak wasn't responsible, he shouldn't be guilty of murder, he'd gone crazy because it was the drug that made him do it. The classic insanity defense.
But consider this: Earlier in the episode, it was said that the drug amplified
Cardassian tendency for xenophobia and paranoia. Meaning, it doesn't create feelings and tendencies where none exist, it merely makes existing ones stronger
. So doesn't this mean that Garak - being a Cardassian - already hates humans and secretly wants to kill them? And therefore, because the drug only brought an existing prejudice and violent tendency out into the open, shouldn't Garak be on the hook for Amaro's murder?
(I do agree with Garak on one thing, though...it would have been a BAD IDEA for Garak to try to apologize personally to Amaro's wife)