His father was a dead man the moment he started playing the game when the king made him the hand and decided to go after cerci. his ego led to his death. Same with rob he thought he navigate shark infested waters the way he wanted to and found it just like his dad that shyt dont fly
Was it arrogance on Ned's part?
I always thought he just didn't know how to play the game. Renly tried to tell him that they needed to kidnap Joffrey and tried to give him the men to do it.
Ned really thought that everybody was gonna stay true to their word cause he never really understood that he was in a snake pit.
And there was no reason for him to ever think about that as long as Robert, his best friend, was alive. He was under the kings protection no matter what he did (his daughter beating up Joffrey, his wife kidnapping Tyrion). He could really get away with murder as long as Robert was alive.
Robert was the only friend he had in Kings Landing and once he got took out by that pig (a literal pig for non watchers who think I'm being facetious), it was over for Ned.
He should have skipped town like Renly did.
Renly had no reason to run, at least the show didn't spell it out. But he surmised (correctly) that the minute his brother died, he was on borrowed time in Kings Landing and so he got out of dodge.