What does it says about Christie if he is telling the truth about Bridgegate? That may be more a disqualification for the presidency than if he is lying.
What does the truth mean?
1) He installed staff so incompetent that, without hesitation, it uses public email to plan the closing. If you are going to do this, be smart enough to access email away from the state servers or use Snapchat. Even an old-fashioned phone call is better. Don't leave a FOIA-subject trail.
2) Christie fostered a culture of pettiness and arrogance. He hired, promoted and encouraged managers who would take this action and believe themselves beyond reproach.
3) Christie installed people so unconnected with reality that the GWB appeared a reasonable political response. There are many acceptable ways to express displeasure. Blocking ambulances, school buses and tying up interstate commerce are not.
4) Christie failed to effectively oversee staff and events. New Jersey is not a large state and a disruption as large as the GWB should have gotten the Governor's attention. His administration should have found what "rogue staff" did and quickly corrected it in real-time.
If not knowing is a true statement, what Christie admits to the inability to administer the state competently. That New Jersey (and New York) residents will be subjected to four more years of arbitrary and capricious acts from reckless and unmonitored administrators conducting political vendettas at the public's expense.
He may well be a better administrator if he lied, and instead ordered the closing and directed staff to get it done in Nuremberg fashion. Not a better human being, but the traffic stopped on time.
So the choice is between Christie lying and being a reckless, fascistic bully, or telling the truth and being one of the most incompetent governors in our time. It ultimately does not matter if he lied or told the truth. Either way, this scandal should forever bar him from public office.