A person or persons of the Tamsinist
persuasion are most likely to leap to the most horrendous outcome of any situation; particularly in medical and public health terms.
To assume the worst possible outcome in a medical procedure is the most likely event. More broadly it can be seen as a general "glass half empty" approach to life and an indication that a Tamsinist} generally expects the worst.
In a typically Tamsinist
fashion, Matthew assumeed his shin splints would result in the amputation of both his legs.
or "There's no doubt that several spots on your face will lead to death" exclaimed the firecely Tamsinist