Regulation helped cause the deaths by driving people to more dangerous sources. You're 'forgetting,' however, that the oxycontin and prescribed pills were the source of those addictions in the first place. The regulations didn't kill them. If the regulations had always been there, they would have been fine. They weren't tamping down on some mystical parallel crisis, however convenient that would be to shift the blame. They were creating a new one, using the legitimacy of the medical system and doctors prescriptions to get people hooked, to fatal effect when the regulations finally came down and people facing addiction turned to illicit sources.