The letter is a singular composition.

It sets out the writer's real and unfeigned desire to have offered his service to King George, but for his liability to be thrown into jail for a civil debt, at the instance of the Duke of Montrose.

Being thus debarred from taking the right side, he acknowledged he embraced the wrong one, upon Falstaff's principle, that since the King wanted men and the rebels soldiers, it were worse shame to be idle in such a stirring world, than to embrace the worst side, were it as black as rebellion could make it.
The impossibility of his being neutral in such a debate, Rob seems to lay down as an undeniable proposition.

At the same time, while he acknowledges having been forced into an unnatural rebellion against King George, he pleads that he not only avoided acting offensively against his Majesty's forces on all occasions, but, on the contrary, sent to them what intelligence he could collect from time to time; for the truth of which he refers to his Grace the Duke of Argyle.

What influence this plea had on General Wade, we have no means of knowing.
Rob Roy appears to have continued to live very much as usual.