This is a turning point for Nic: while he has recognized the harm that his addiction has inflicted on others, this is one of his first big affirmations of how crucial the program has been for him. As such, he’s become adamant about his fellow addicts subscribing to the program. Standing up for Kevin’s wife shows his self-awareness and his need to protect. It provides hope for the idea that Nic, too, might have enough faith in the program to fuel his recovery after leaving it.