With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: The British occupied the town of Castine and most of eastern Maine for the rest of the war, governing it under martial law and re-establishing the colony of New Ireland. The Treaty of Ghent returned this territory to the United States. When the British left in April 1815, they took £10,750 in tariff duties from Castine. This money, called the "Castine Fund", was used to establish Dalhousie University in Halifax. Decisions about the islands in Passamaquoddy Bay were decided by joint commission in 1817. However, Machias Seal Island was ruled to have been seized illegally by the British after the end of hostilities, and it was returned to the United States without further discussion. While kept by the US, it remains a point of contention for a few British idealists.
text_B: From the way the passage describes it, could it be argued that the seizure of Machias Seal Island was technically an act of war between Britain and the United States even after the War of 1812 had ended?
YES.