Sorry not to think of querying the info in your original post. The confusion of names did make me wonder whether there had been some sort of error. Like Dotty, I fairly regularly send in corrections to Ancestry.
Your ancestor's brother Thomas Barnes Vaughan lived in Dollar, Clackmannanshire. He's on the 1861 census with his wife and 5 children - all are shown as having been born in England. Contrary to Dotty's thought that he might have ended up in London, he died the same year still in Dollar. His father is given as William Vaughan, landed proprietor; his mother as Mary Vaughan, nee Barnes - both are shown as having pre-deceased him.
His death was the result of accidental poisoning - a confusion between two drugs. The circumstances were reported to the Procurator Fiscal who must have satisfied himself that there was no evidence of foul play nor of suicide.
I have viewed the census record and the death certificate and so could send you copies if you are interested.