I learned the hard way as most of us do, we have to see it, feel it and witness it for ourselves. The relationship with an addict is learned sadly by experience. He has a history behind him of previous arrests for drugs, court ordered rehab, therapy, etc. YET he used, got arrested and repeated his whole cycle all over AGAIN. Maybe this time was his last and maybe it’s not.
A pretty good prediction for someone’s future behavior is with their past behavior. I wouldn’t put all of your hopes and dreams into him changing unless you WITNESS that change because words don’t mean a dam thing.
Sure his plan includes getting a job and staying sober but HOW exactly is he going to execute that plan? For staying sober? What’s he going to do differently this time then the times before? What did he do while in jail for his sobriety? Did he attend AA work with a substance abuse counselor?