I agree, very interesting.
It's one of several reasons serial killers are caught and why the profile is narrowed for regular homicides.
A killer that looks back in the timeline and remembers TB's wife's smile, might feel that trying to separate himself from the body at the point of dismemberment/burning, etc. will stop any trail from leading to him.
Some other dismemberment/disposal motivations can center around job skills, profession, tools at hand, location etc. Google Gary Carl Simmons Jr., a personal case but be forewarned.
Anyway, it doesn't stop the trail, it just adds more to the profile and evidence that convicts. For ex. Gary's downfall was the stupidity of defacing the finger/footprints but left the face on the decapitated head when he disposed of the "body parts" in the bayou. Which spoke volumes and which led to his arrest, conviction and just extermination by lethal cocktail, June 20, 2012.
Not sure how fast things progress here but by now it should be abundantly evident that the two they have are the correct ones or they should be close to announcing a release of suspects.
moo