Probably not, he wasn't known for giving quarter, but I don't think anyone contends there's any basis for the Church incident, and I don't think there's any basis for portraying him as killing women, children, or prisoners en masse as in the "hospital" scene.
Did the Brits Burn Churches?
Couper Samuelson
Posted Monday, July 10, 2000, at 3:00 PM PT
In the new Mel Gibson film The Patriot, British soldiers are shown committing various atrocities against colonials during the American Revolution, such as locking civilians in a church and setting it on fire. Did the British actually violate the rules of war as the film alleges?
Many histories of the war document instances in which British and American soldiers shot prisoners of war or, more commonly, enemy soldiers trying to surrender. (This was considered a violation of the rules of war at the time and remains so today.)
Lt. Col. Banastre Tarleton--the model for The Patriot's main villain--reportedly killed more than a hundred colonial prisoners in South Carolina and was dubbed "Bloody Ban." The term "Tarleton's quarter" signified no quarter at all.
The journal of Thomas McCarty, a sergeant in the 8th Virginia Regiment, reports that British regulars shot civilians (at least two of them women) who were tending to wounded colonials after a nighttime engagement near New Brunswick on Feb. 1, 1777. After a skirmish in Newtown, N.Y., in 1779, two lieutenant colonels under Gen. John Sullivan were captured by the British. A fellow prisoner, John Salmon, recounted in his diary that when the two officers refused to give up the location of Sullivan's army, they "were put to death with terrible torture."
But historians generally agree that the rebels probably violated the rules of war more often than the British. Francis Marion, who led a band of militiamen in South Carolina (and whom Gibson's character most closely resembles), ordered his men to fire upon a group of British regulars and American Tories who had surrendered. A witness described it thus: "Numerous Tories died with their hands in the air."
In 1778, Georgia militiamen captured, stripped, and killed British Lt. John Kemp along with nine of his men for refusing to renounce the king. And the term "lynching" comes from Col. Charles Lynch of Virginia, who became famous for extra-legal executions of Tory sympathizers.
The church-burning scene in The Patriot is actually based on an incident from World War II, when Nazi soldiers burned a group of French villagers alive. There is no evidence that a similar event took place during the American Revolution.
Couper Samuelson is a Slate intern.
The link I posted said "he never spared prisoners" (but I don't remember "the 'hospital' scene", so I could be making a bad comparison).
I haven't seen anything about women and children yet.