A better argument could be made that archaic anti-drug laws killed Daniel. It's the nature of an uncontrolled black market for nefarious types to cut drugs with dangerous substances to increase profit margins. In this case it was Levamisole.

From wikipedia: (https://en.wikipedia.org/wiki/Levamisole#Toxicity)

  Levamisole may be quantified in blood, plasma, or urine as a diagnostic tool in clinical
  poisoning situations or to aid in the medicolegal investigation of suspicious deaths 
  involving adulterated street drugs. About 3% of an oral dose is eliminated unchanged 
  in the 24-hour urine of humans. A post mortem blood levamisole concentration of 2.2 mg/l 
  was present in a woman who died of a cocaine overdose.[

So this isn't the first time this has happened.

I really feel for the family: but if they want justice and to avoid this happening again, a frank admission that preventing people from experimenting is virtually impossible needs to be made. In the interests of public health it's preferable that at least there be some control to ensure people aren't ingesting poisons.

Limiting access to drugs usually gets in the way harm reduction. What happened was a shame, though.

Because he never could have bought those drugs using regular cash. Ridiculous.