The FAQs section has numerous answers to questions similar to yours.

The short answer I can give you is that it is false. Not only does it ignore the ample experience the British had with guerrilla warfare in previous conflicts in the Americas and elsewhere, but the utilization of such methods by both sides during the war. It also ignores the pains and great lengths Washington went through/to to develop the Continental Army into a competent, well-trained and equipped Army, capable of taking on and defeating the British in conventional battle.

Throughout history, regular armies have prepared to defeat their opponents in one type of battle and tend to have institutional preference for that type of battle - and often a disregard for other types of battle as unproper.

British regular infantry was well-drilled and relied on superior discipline and drill to deliver an advantage in firepower and moral fibre on the battlefield.

Infantry marched and fought in closed ranks since they needed such formations to be able to work together (a unit that could not be controlled and commanded would be useless, and how far the officer could shout to his NCOs over the sound of battle would really determine how for out you could space troops), it needed to stick together to not become an easy prey to enemy cavalry and they needed to be able to deliver salvoes of msuket fire for maximum effect against the enemy, both in casualties and to their morale.

Combat for regular infantry could be described a bit like a chicken race. The unit that fired last would fire at a closer distance and do much more damage. Keeping formation and discipline while under fire and suffering casualties established a moral superiority over the enemy unit, which could make them break and run.

This is why regular infantry in the revolutionary war fought like they did.

Did that mean that guerilla and light unit tactics were not used? Certainly not. While light infantry really came into their limelight in western Europe during the Napoleonic war, they were used during the 7 years' war and to a limited extent even earlier. However, in eastern and southeastern Europe, hit and run tactics were common. While the difference between bandits and light infantry can sometimes be a bit of a blur, Bosniaks and Albanians in service of the Ottomans would use guerilla tactics and hit-and-run attacks, fighting in dispersed formations from rough terrain against their Austrian enemies.

All European nations also used cavalry for skirmishing, patrolling, recoinnasance, foraging, devastating the terrain (looting and burning to deny the enemy supplies) - small groups of cavalry or dragoons would fan out in the terrain, acting as the eyes and ears of the commander, but also his tools to deny the same thing to the enemy. Skirmishing and hit-and-run attacks on enemy patrols, supply transports, reinforcements or even camp was common.

The Ottomans used their akinci and deli light cavalry in this fashion, and the Austrians recruited Croat light cavalry and Hungarian hussars to counter them - and through the Austrians light cavalry and its uses spread through Europe - by the end of the 7 years' war most European nations fielded their own hussars units, dressed and equipped like the Hungarian ones (the fur jacket over the left shoulder, protecting against saber cuts, for example).

The Russians used cossacks in the same fashion to combat the light cavalry of the various Khanates in Central Asia and the Crimea as well as the Ottomans.

The British had fought the native americans quite a bit, as many of them allies with the French during the 7 years' war (called the French and Indian War in the US, if I recall correctly), so the tactic was not unknown to them.

One should remember that many of the British troops that fought in the Revolutionary War were among the worst British troops - The King's German Legion and the Hessian mercenaries were not known as the most disciplined nor the best of the redcoats and that the British had severe problems getting a large enough cavalry contignent to the colonies due to the distances involved.

One should also remember that in order to actually defeat the British, Washington had to build the Continental Army into a regular force that fought with the regular European tactics - not only did these troops win at Yorktown, the existance of a US regular force capable of fighting in the open field meant that the British had to keep a regular army gathered in New York and could not fan out and occupy the countryside.

Guerilla style warfare cannot prevent a regular force from occupying terrain, only make its path there difficult and its existance in the occupied territory difficult to impossible.

Max Boot's "Invisible Armies" is my go-to guide on guerrilla warfare. From his chapter on the Revolutionary War (scanned using Text Fairy if you see typos):

Washington rejected the suggestions of Major General Charles Lee, the third—ranking officer in the Continental army, who advocated a petite guerre strategy in which small detachments of armed rebels would avoid pitched battles and harass the enemy forces until they were exhausted. Lee was a former British officer and a self-professed “eccentric” who had more than a little in common with two future visionaries of irregular warfare, Orde Wingate and T.E. Lawrence. Like them, he amused, alarmed, and alienated his fellow officers in equal measure. He argued that it was a mistake for the Americans to maintain an army on the “European Plan" and that a "plan of defense, harassing, and impeding can alone succeed." Washington, on the other hand, preferred to create a disciplined army that would be able to beat the British regulars at their own game. The historian John Shy suggests that Washington and other rebel leaders “stressed a regular army . . . because they felt a need to be seen as cultivated, honorable, respectable men, not savages leading other savages in a howling wilderness."

But even though the Continental army would become the mainstay of the revolution, state militias performed such vital functions as suppressing Loyalist uprisings, gathering intelligence, and impeding enemy movements.” On occasion they even played a leading role. And for all his antipathy to the militia, Washington was enough of a pragmatist that he was willing to take advantage of their efforts when they proved their worth.