For instance, imagine you have surgery, and die of a complication. Your relatives will feel very differently, and be in a very different legal situation, if the hospital's explanation is "surgeon was the bottom of their class" vs "yeah, we just handed a visiting 5 year old a scalpel to see what would happen". Neither are ideal, obviously, but the latter is _criminal_.
The idiot in the article is clearly closer to the 5 year old than the scraping-a-pass surgeon; he is simply not in any way a proper person to have been given the sort of access or authority he was, this would have been obvious to whoever gave it to him, and whoever gave it to him is at least morally culpable.