The burden of responsibility is on the person claiming that it is responsible for death. LSD, the substance, has not killed anyone. Someone is welcome to disprove this.

The effects of LSD, the substance, certainly have.

The substance itself does not cause an "overdose" and the same is true of cannabis (at least for any ingestible amount), but it would be disingenuous to claim they have not caused deaths.

No, the burden of responsibility is on people not to say stuff that's trivially disproven with a simple Google search. Though I'm guessing most HN commenters already know the story of Frank Olsen without even having to do one.