On what scientific grounds? As far as we know it's a one man job. An authentic experiment has to be done like for like. That means not only Aga which has to be not only the same model, but the same height, using the same fuel and crucially, the same temperature. Do we actually have information about the temperature of the Bambers model? The human model would need to replicate Nevill in height and weight, maybe age, too. It would also have to be replicated by other scientists for authenticity. It's a known fact that experiments can be made to say what we want them to say.
If I may answer, Jane, I think you're being a little too scientific!
The main thing in my opinion is the spacings, this is what essentially ties the Aga to Nevills back!
Thats all we need to prove beyond a reasonable doubt that the cooker caused the burns.
The variation of the top mark being explained by Nevills head bent forward while against the apparatus,