I suspect he was a "roguey" because he was slyly drumming up Jacobite sentiment.

The OED has "rogue" in the sense of "A mischievous person, esp. a child; a person whose behaviour one disapproves of but who is nonetheless likeable or attractive. Freq. as a playful term of reproof or reproach or as a term of endearment" from so long ago as 1593.