I think this is one of those things that you should talk to him and his doctors about. I personally only have bipolar 2, so I don't usually do long-term damage during my hypomania. Everyone has a different level of insight about their diagnosis. Some people who have bipolar 1 with psychotic features completely lose insight, while others have insight into their condition and simply don't care. If the diagnosis is recent and/or he is making an effort to control the symptoms and his behavior, you should recognize that. But if he has had this diagnosis for a long time and does not seek help when an episode comes on, then I think he has to take more responsibility for his actions. Does that help?