I don’t really have a bone in this whatsoever, but the cause of death in an overdose can sometimes be different than the listed cause of death.
For example, if you have a man dead with a heroin needle in his arm, you can probably guess he dies from a heroin overdose. But if the toxicology report says they find traces of, we’ll just say, caffeine, then they “can’t prove” the caffeine didn’t cause or contribute to the overdose so the death will be labeled as natural causes or unknown cause of overdose, I’m not a doctor, I don’t know the official terms they use.
I used to help work overdose investigations in Knoxville and we definitely had a weed laced with fentanyl death, but it wasn’t listed as a fentanyl overdose because they couldn’t definitively say that fentanyl caused it.