Isaac's invention of a musket with a spyglass attached would be totally pointless, as the lack of accuracy of smooth-barreled weapons is not related to the distance the shooter can see at, but because of the barrel not being rifled. Yet, the invention proves to be quite accurate.
When Samantha is with the contractor, Mark, to disassemble the shed Lieutenant Colonel Nigel Chessum comes out with his men protesting the barracks as the sovereign territory of "His Royal Highness King George III." A British officer of the Revolutionary War would have referred to his monarch as "His Britannic Majesty King George III" and would not have used the title "Highness," which is used to refer to princes, not kings.
Nigel Chessum introduces himself as Lieutenant-colonel using the American pronunciation. British army officers, even in the Revolutionary War, pronounce at as "Left-tenant".