It turned out it was the paediatrician's dad. This is long so pay attention...lol.
Harry found out that the hospital team had covered up for the Chinese nurse and paediatrician. They had messed up an op on a little girl and tried to hide it. Her dad was trying to stop it getting out and killed the lot of them.
It turned out he was in the army with the funeral parlour's boss ( who died ). He had saved his life in the army . so when the dad killed the 1st bloke , he got his m8 to hide it in the coffin.
Then at the end he shot himself in the head in full view of his daughter and Harry.Hope this helps:-)