In 1832 Vidal was seriously wounded in the Portuguese War of the Two Brothers. He was acting as interpreter to the admiral's flag captain and they went on shore in Oporto to observe a Dom Pedro military position which, however, came under attack from a Dom Miguel force. He was pierced through the body (two sources say through the liver) by a musket ball. A British officer told the "Sunday Times":Mr Vidal, the admiral's purser [has] been shot through both sides above the hip. He is not yet dead, but his case is a bad one. He was a gentleman universally respected in the fleet, and his wound is deeply deplored. Some newspapers reported he was dead. One source recalled that Vidal was brought back to a British ship bleeding, in great pain, in an open boat.