We do know why! (Terrible headline...)

These weren't psilocin/psilocybin edibles made from natural psychedelic mushrooms. These chocolates contained synthetic tryptamines[0] (related chemicals to psilocin/psilocybin) such as 4-AcO-DMT, with poor quality control of doses/concentrations.

This is a direct result of patchwork prohibition laws. If psilocin/psilocybin were legal nationwide and well-regulated, it could be provided in a variety of forms with high purity, real quality control guarantees, and accessible independent third-party testing.

0: https://arstechnica.com/science/2024/07/illegal-drug-found-i...