he was a recovering addict. I didn't se any support groups, he didn't go to Narcotics Anonymous (NA), he let his years of clean time catch up to himself without a "one day at a time" thinking process.
Addiction is a permanent condition; one can stay clean with daily desires to do so, along with at least periodic support groups, personal inventory - basic stuff of rehabilitation. If one doesn't do this, one is more likely to lapse.
Seems like he didn't really try to "work the program" - not going to judge him though, addiction is insidious, and manifests itself different ways for different people. Once you have the disease it has to be acknowledged can't just say "well i'm clean now"