Barristan the Bold is not a true knight

[willofDorne]

Were it Stannis and not Ned, I think Barristan and many others would have rallied to make more of stand. However, in Barristan's eyes, a man who had not a drop of claim to the throne was making accusations about the throne. There's nothing he can do, he must protect the royal family. Do his job, even if that means dying. When we get his POV we hear him thinking about what this job is, it's constant guess work at who will attack the king next, and cutting off angles against them. He doesn't have time to consider other things, one slip and another king bites the dust.