DH--bipolar DWI

Well, it shocked the heck out of me, but really, it didn't.
DH's friend Jim came on Memorial Weekend for a visit. He and DH went out to "shoot pool" and "have a beer or two". Now just to clarify, DH does not drink often. Maybe once or twice a year. But when he does, the concept of "Social Drinking" kind of goes out the window. It's "all or nothing" for him.
When he does want to drink, I'm always concerned, because the Lithium and Depakote can intensify the effects of the alcohol. He half-jokingly asked me how many beers he could have, and I said "two or three, no more!" and he said "Oh! I was thinking I could only have one or two!" So since he was aware of the fact that I thought he should limit his intake, and because Jim (who tends to be very responsible) was going along and also driving, I didn't worry much. I went off to work my overnight shift at the 2nd job.
When I got home in the morning, DH's car was gone and so was Jim's. I knew that Jim was going to leave for his home early in the morning, so the fact that his car was not there did not surprise me. In fact, I wasn't even very concerned that DH's car was not there, I just figured the two of them went out to breakfast before Jim left (Jim always takes DH out to eat when he visits). So imagine my surprise when I went into the house and there was DH! "I got arrested," he said.
It turns out that DH and Jim had only had one beer at the bar. On the way back from the bar, Jim, trying to be generous, as money is still tight and I never give much to DH, gave DH a $20 bill so that DH could have some spending money. Jim went to bed, DH got in his car and went back to the bar.
According to DH, while he was at the bar the 2nd time, the man sitting next to him kept buying him drinks. DH knew he was pretty drunk when the man offered to share a joint with him. Now, in the history of our marriage, I honestly do not believe that DH has smoked pot. But of course he did on this fateful night. He then got in his car to go home, it was 8 miles on a rural road.
DH doesn't remember much of what happened after that. Apparently he couldn't find the right road to go home. He ended up 43 miles away from home, having hit a guardrail (on the drivers side, yet--if that tells you anything) and being pulled over by a police officer who had to swerve to avoid being hit by DH in the oncoming lane.
The police report states that DH said to the officer "I'm bombed and need to go to jail!".
So he did. Jim bailed him out before I got home, then Jim left, to avoid the fireworks.
So. On our tight budget, it cost 300.00 to get his car out of the impound. $800 in fines and court costs, and $720.00 to get his license back after 90 days of suspension. In all fairness, DH did do community service to pay the court fines. I told our insurance agent that DH got a DWI, the agent said "I never heard that." and told me that the auto insurance company might not find out. I very much hope not.
Anyhow, as part of his sentence for the DWI, DH had to do an "alcohol assessment", where they basically try to determine whether there is a problem or not. Based on what DH told the probation officer, the probation officer determined that DH needed some kind of treatment. Both for the drinking to excess and the Percocet. And I'm glad for that. DH....well, he just keeps saying how sorry he is that he was honest with the probation officer.
As it becomes clear that this bipolar thing is permanent, I am finding myself better able to recognize that DH's thinking doesn't make sense and I'm not likely to convince him otherwise.