Movies aren't history, but dramatizations of historical events or periods. While I know of no incidents of civilians being rounded up and burned in churches, the British Army, Loyalist auxiliaries and Germanic mercenaries behaved abominably during the war. Rape and pillage were routine and the British frequently gave no quarter, and those prisoners they did take were horribly mistreated.
The historical Banastre Tarleton was at least as villainous as the Patriot's fictional Colonel Tavington. Banastre Tarleton came from a family of slavers and purchased his commission after having squandered most of his inheritance on the usual vices of women and gambling. He was less introspective than the Biblical prodigal son, thus having no father to return home to, he joined the army of the original "evil empire." Tarlton's conduct so alienated the colonial population they flocked to the patriot cause. His massacre of Americans at the Waxhaws enraged the patriots and contributed directly to reprisals against loyalists. It's worth noting that the patriots executed the loyalists who surrendered at King's Mountain because of "Tarleton"s Quarter".
The British occupation of New York City and the New Jersey campaign were designed to unleash as much terror as possible on the colonial population. Thousands of American soldiers were intentionally mistreated to encourage them to enlist in Royal service. Lord Rawdon wrote to his uncle on September 23, 1776, “We should (whenever we get further into the country) give free liberty to the soldiers to ravage at will, that these infatuated wretches may feel what a calamity war is.” Writing of American women living under British "protection" in New York he stated: “The fair nymphs of this isle are in wonderful tribulation as the fresh meat our men have got here has made them as riotous as satyrs. Should a young woman innocently step into the bushes to pluck a rose, she ran the most imminent risk of being ravished and they are so little accustomed to these vigorous methods that they don’t bear them with the proper resignation and of consequence we have most entertaining courts-martial every day." In other words, a British aristocrat, a "stakeholder" in the imperial oligarchy found the resistance of women to being raped as laughable as it was futile.
The behavior of British forces encouraged Americans to fight against, rather than submit to Royal authority. The murder of Jane McRae perfectly illustrated the meaninglessness of British "protection." If a good girl like Jane McRae who was betrothed to a loyalist officer in Burgoyne's army could be slaughtered, and her murderer's unpunished, what sane or decent person would wish to swear fealty to a tyrant or seek protection from such terrorists.
Whatever the "historical" shortcomings of Mel Gibson's movie the Patriot are, it memorably portrayed the brutality of a British army of occupation that encouraged the population to resist and assert their independence.
