In part, that is true. More important, however, is the principle behind the majority decision. The background was that during the miner's strike, the executive of the state suspended habeas in the county where the mine was located because of the miners' insurrection and the inability of the local authorities to control the situation. The governor called out the National Guard to enforce the law. The miners' union boss was arrested and held without trial, until the situation was resolved. The union boss claimed he was held without due process.
Oliver Wendell Holmes, Jr., wrote the majority opinion. Holmes was a Union Civil War vet, who had been several times wounded in battle. Holmes wrote, "That means that [the executive] shall make the ordinary use of the soldiers to that end; that he may kill persons who resist, and, of course, that he may use the milder measure of seizing the bodies of those whom he considers to stand in the way of restoring peace." This constitutional principle, as applied to ACW, would have allowed Lincoln similar latitude. Wherever insurrection or rebellion existed, including those areas of the country not purporting to have seceded, such as Maryland or Missouri, the President was empowered to take those actions he thought necessary to protect the public safety and to preserve constitutional law and republican government.
In Moyer the arrest occurred during an ongoing insurrection with associated violence taking place, and after authorization by the Chief Executive of the State, and State forces were used.
In Merryman, the arrest occurred a month after any violence had ended, Merryman was sleeping in his bed in the middle of the night, and the Chief Executive had not authorized the arrest, the Governor did not request it, and Federal forces were used.
The attempted application of Moyer to the facts in Merryman does not pass the giggle test.