"The fire had been confined to the sitting room. The only damage was to the body, which was totally burnt, the ceiling above him and the floor underneath him."
I recall seeing an interesting special on public broadcasting about SHC. What is described is typical of these cases.
A person falls unconscious or dies in an enclosed room, and the clothes catch fire (cigarette or, in this case, probably a spark from the fireplace). The flames use up most of the oxygen in the room, so the flames die down, but don't go out completely - they just burn very slowly. So there's little damage to the surrounding room, but because of the low flame, the body burns almost completely.
It's called the Wick Effect - which is ironic since there is a county in Ireland with that very name (spelled differently).
Perhaps this guy should be sent there as penance for this ludicrous abandonment of science.
I just discovered there's a wikipedia article for wick effect.
The body fat melts into clothing fabric, which can burn like a candle for hours. I'm not sure about the scientific principle but I think the cotton turns completely into carbon while retaining its structure like a kerosene lamp wick.
The wick doesn't burn because it conducts the potentially combustible material (fat) which is vaporised by the heat - the vapour burns, but the liquid does not and that stops the material from being consumed. Much the same thing happens in a wax candle. The balance is delicate, of course, but it happens often enough to see that this is what's going on.
This was done with a pig carcass some years ago and the burn takes many, many hours but the localised heating does not burn much around it. It's interesting stuff but not very magical - this coroner should consider his position.