1. Christie knew about it.
2. There's no evidence anywhere that he knew about it.
3. This had nothing to do with politics and was part of a jurisdictional pissing match between the state of New Jersey and the town of Fort Lee over access restrictions to the George Washington Bridge.
If you can't tell, I'm very anti-Chris Christie. A smug self-aggrandizing abrasive blowhard do nothing jerk who accomplished two lasting things: Saved Obama in 2012 and made the one cheap thing we had in NJ, gasoline, expensive. Oh yeah, and all his recommendations to Trump for staff positions appear to have been deep state hacks that have worked to undermine Trump.
Other than hurting the feelings of the teachers unions in his first year in office before backing down, what else has he done?