 O'Donel's ministry in Newfoundland was largely characterized by trying to maintain peace, both between fellow Catholics and with the British.In 1800, an incipient Irish uprising involving soldiers in the St. John's garrison was forestalled when O'Donel, upon hearing of the plans, alerted the authorities.The 19th-century historian Charles Pedley alleged that O'Donel received his information via the confessional, but credible evidence for this claim is absent

O'Donel's health deteriorated in the early 19th century, and he resigned his position in 1807 and returned to Ireland.