Could a human survive being cut in half at the waist if person who did it was not surgeon but someone with knowledge of how to stop bleeding and avoid infection?

Surviving being cut in half at the waist is highly unlikely, even with medical intervention. The human body is incredibly complex, and the chances of successfully reattaching the upper and lower halves are extremely slim. Even if the person who performed the procedure had extensive medical knowledge, it is doubtful they could provide the necessary level of care and expertise to ensure the survival of the victim.