From Gwulo: Old Hong Kong
There is some more about him on page 590 of the History of the laws and courts of Hongkong by Norton-Kyshe:
On 2nd June, 1859, a brother of the now famous Mr D.R.Caldwell, the Registrar-General and Protector of Chinese, named Henry Charles Caldwell arrived in Hong Kong from London by the ship Northfleet. He had previously been Registrar of the Recorder’s Court at Singapore and was a fugitive defaulter from there, having some years before embezzled trust moneys in his official capacity. Ever since his detection in 1856-1857 a backed criminal warrant from Singapore had been lying in the hands of the Superintendent of Police at Hong Kong for execution at the moment of his expected arrival in the Colony, his wife and family having preceded him. Yet on Mr H.C.Caldwell’s arrival, not only was he not arrested but actually allowed to depart out of the jurisdiction the same night for Macau, where his brother, Mr D.R.Caldwell, had previously obtained a residence for him and where he was to carry on the business as a notary and general agent amongst the Chinese. By what influence Mr H.C.Caldwell was thus allowed to escape the meshes of the law is not apparent, but suffice it to say that the matter did not escape Mr Anstey, who at once brought it to the notice of the Secretary of State. The local press also took up the subject in strong terms, but Mr H.C.Caldwell was allowed the greatest immunity from any possible interference.
How he got out of his difficulties and whether he or others on his behalf “compounded his felony” is enveloped in mystery, but he eventually found his way back to Hong Kong and entered the office of Messrs Cooper-Turner and Hazeland, solicitors; then he articled himself to Mr R.C.Owen, the barrister (who under the provisions of Ordinance number 13 of 1862 had elected to act as an attorney), being admitted some years after as an attorney and solicitor of the Court. He soon made for himself a lucrative practice and became one of the leading solicitors in Hong Kong. Another of the wonderful incidents in regard to the history of this Colony. Mr H.C.Caldwell having amassed a competency retired to England, and died at his residence at Twickenham, England, on 28 June, 1883, at the age of sixty-eight.
From: https://archive.org/stream/historylawsandc00nortgoog#page/n633/mode/2up