Normally that's how they draw the line on intention.I'd guess the reason the death was ruled accidental was no suicide note was found by or presented to authorities. My understanding is coroners tend to err on the conservative (accidental) side in such cases due to the legal (probate/insurance) impact of a suicide ruling. Hopefully now his family can get some closure.
I understand the hydrocodone, as it is also used as a cough suppresent for COPD. But the oxy is normally not combined with the Hydrocodone. Both are for pain, both are opiads. Soma and valium also depress breathing, which is something you don't want to do with a COPD patient.