[pan naranus]

I think Ned was just out of his natural territory.
Up north he was the ultimate arbiter of power - his word was sacred so being so honorable was of a great value. in court however he was another player, a vary bad player dew to early experience.
Ned could not, and probably should not lower himself to the level of littlefinger (my candidate for starting the war - Lying to cat about the dagger, persuading liysa to kill her husband, misleading Ned on the subject of gold clocks loyalty...) but then, he should not have gone south in the first place. 200 archers on moat ceiling and the hell with all the rotten kingdom was the best coerce of action. Sending investigators - better suited for the job to check about the death of Jon ayrin (the matter of the attempted assassination on Bran was not an issue at the time as I recall).
But that's evolution for you...