Goofs

When Brienne is writing about Jaime in the White Book, a paragraph mentions that Jaime took Riverrun "without loss of life." Brynden "Blackfish" Tully died (off-screen) when Riverrun was taken (Season 6) and at the time it was also mentioned how he managed to slay a few Lannister soldiers before being killed. So there evidently was loss of lives on both sides. See more