IMO, there are tragic flaws and there are inconceivable acts which are done for the same dramatic effect as the offenses we’ve been writing about. It is simply a matter of how quickly those actions kill your ability to suspend your disbelief.
The instant Tyrion saved Catelyn’s life in the battle with the hill people and Cat refused to change her mind about him, while still aware that her family was in danger in Lannister-held King’s Landing, this was an unforgivable plot hole. Her subsequent blubbering about her children and then releasing Jamie when Robb could have negotiated a much better deal to get back the girls is also an unforgivable plot hole. Nobody could be that stupid and short sighted.
But it gave us the wonderful scene where Tyrion demands trial by combat, Bronn becames an important character, and Tyrion is set on the path to bring the hill people into Tywinn’s battle.
It took me longer to ponder the issues with Ned and Jamie, so I’ll grant that GRRM’s offenses were not as egregious as those of B&W, but they are still unforgivable plot holes that lessen my view of the quality of the books and show, or my ability to rewatch old episodes.
Notes on Ned and Jamie:
Ned’s most sacred oath was to his sister. He implied as much when Robert complained about her being buried in the Winterfell crypts. Allowing Jon to join the Night’s Watch was not the way to protect her baby. He couldn’t possibly be so stupid as to think Jon would have any kind of a life up there. (If you were dying in child birth, I would think you would want your brother to know that you loved Rhaegar and married him as a means of reinforcing how important your son is to you and also saving your own honor.)
Jamie grew up in a culture which abuses children and shows them almost no respect. We have seen so many instances where the higher born person’s word carries more weight, regardless of the evidence. As a kingslayer, he already was dealing with complex moral issues while having arguably one of the highest moral codes of any character.
I would argue that Jamie is more honorable than Ned, as his choices and omissions of truth cost him far more than Ned. Ned chose to live his life as the man who killed Arthur Dayne in battle. He could have easily said that Howland Reed saved his life without ever mentioning what happened in the Tower of Joy. Jamie not only saved an entire city at the cost of his reputation, he risked his life three times (saving Brienne from being raped, saving Brienne from the bear, charging at Dany and Drogon), while Ned refused to do his duty by not exposing Cersei’s affair while Robert was still alive and then confessing to being a traitor to save Sansa.