The mixed dna traces found on the right rear area adjacent to the damaged tail light, along with the little hair that could (collected from a different location on the right rear area and equally not exclusive of John or any relative of his in the female line) are probably some of the most stand out non-evidence 'evidence' presented by the cw in this trial Imo.
If the cw had swabbed for DNA on other areas on the rear of the vehicle, including the rear left hand side near the tail light, the hatch area and surrounds, the window etc etc, I'm sure they would have found traces of John. Ofcourse the cw was not willing to do this because of the risk of normalising the non-evidence. Moo
The defense never insinuated, and it was not part of their defense, that the DNA was planted moo, so I think the OP is mistaken if that is what is being assumed. The jurors were not asked to consider that at all. The point is there was just too much doubt about when the epithelial DNA could have been transferred. It seriously could have happened any time. It's like trying to argue that a victim's DNA found in their partner's home is meaningful evidence that their partner committed a crime against them in that location. Jmo
Ebm a sentence