I have to disagree to a point. I think it was a combination of matches lighting the keg. In no small way was Jaime not part of that considering he created the problem by a) ****ing his sister and b) fathering her children, thereby committing treason against the king which inevitably would set his family on a crash course with someone, be it Baratheon, Stark or even Arryn (and as it turned out, it was all of the above).
He also pushed Bran out the window. Yes, he did it to save Cersei and their children's lives (as well as his own), but it was truly the match to the powder keg.
I think Jaime is an infinitely complex figure. One who I really grew to sympathize with and understand while reading ASOS and AFFC. He has most of the best scenes in the latter and, as you know, we are only getting the first glimpse of his depth in the last few weeks.
However, I think too many readers mistake his level of depth or interesting fascination with righteousness or aggrievement. The truth is that characters like Jaime are much more interesting, as we go along, than Ned or Cat. So, their mistakes are often condemned far more harshly. While Jaime's are often glossed over because he is so interesting. Lest we forget, Ned had his son crippled by Jaime and his best friend murdered by Cersei and Lancel. Nor is Jaime beyond reproach in vanity and ego, such as his very next line "BY WHAT RIGHT DOES THE WOLF HAVE TO JUDGE THE LION!"
Just a thought.