When Brianna was telling her parents and Roger about the Battle of Alamance Roger goes to tell Murtagh. When she was sharing the info Roger's beard was short with not a lot of hair, but when he arrives to warn Murtagh which is supposed to be the same day or at least shortly after his beard is significantly hairier.
In previous episodes the infant son of Brianna and Roger had dark brown hair like theirs. In this episode, which emphasizes that the baby might be Bonnet's son, the child is now fair-haired like Bonnet.
Sam Heughan's shirtless physique is seen when he bathes in the creek. It is impossible for a man in his character's situation to have such a physique unless he is engaged in hard labor. Heughan's obvious weight training may make him more interesting to female viewers but it is in conflict with the character he plays.