The terms psychopath and sociopath have been thrown around so thoroughly by fictional media that they have very little actual meaning any longer. Neither one is an actual medical diagnosis.

Thomas Harris also didn't want to write Hannibal Rising. He wrote the book and adapted it to a screenplay under threat of losing his rights to the character altogether. I suspect he wrote himself in circles until he felt like he was done and slapped a cover onto it. Some continuity errors are to be expected.