sounds like you have a bit of a pro psychedelic bias here and are minimizing people's experiences. This isn't just some story I heard, this is a person that I know and who I witnessed struggle to heal from literal broken bones over years.

"as far as I know it happened only once provably" = "I haven't heard of it, so it must not exist or be a lie". Pretty unproductive perspective to have...

I find your kind of flippant "well they just didn't do it right" approach a very common defense of various forms of dogma. Maybe you should consider that mind-altering substances can have consequences for even those who approach them in the most responsible way possible.