Agreed. I work in a hospital morgue and am also studying human anatomy (mostly bones and evolutionary stuff, but there's a lot of human bio in there) AND I'm minoring in criminology to boot. That stuff is all 100% true. All I could think throughout the Jeff story was how implausible it was.
Eyes would dry out. Infection would set in. Story version could probably talk okay (although the scar tissue would tighten the mouth and make speech more difficult) but not the photo version. Household bleach basically cannot lighten skin in that manner. Doctors don't dramatically unbandage faces and a teenage boy (especially one who had recently developed violent tendencies) who had suffered such extensive damage to his face would definitely be forced to undergo trauma counciling. His behaviour would never have been blamed on drugs, because heavy painkillers don't make you behave that way. You can't just 'gut' two people who would be struggling (especially since there was a gun nearby!) and fighting back with all their strength, especially when they're bigger and stronger to begin with. Kitchen knives probably wouldn't be sharp enough to actually gut a person from sternum to groin. Knives are extremely difficult murder weapons to use because they become slick with blood and that leads to the user cutting themselves up and/or dropping the knife. The police would doubtlessly be able to catch an inept, psychotic teenage boy pretty easily.
That's why I wanted to write a story in response where the killer is portrayed as naive and inept, who idealises the idea of using a butcher knife as a weapon only to find that when he attacks his prey she fights back incredibly hard, when he stabs her he just causes defensive wounds, he cuts himself on the knife, when he's actually able to get the drop on her and stab her in the chest he just hits bone, she's able to overpower him and, in fact manages to kill him.
It's basically what would actually happen if a teenage boy pulled a Jeff, without the stupid cliche psychotic break or self-mutilation.