I don't think Christie should have ever run for Prez. Like it or not, people have biases against obese politicians. Back in the days before television it was a different story because being overweight meant wealth and therefore something to aspire to, but today people are more concerned about looks. His "tell it like it is" style was somewhat attractive and different, and certainly not abrasive when compared to Trump, who is in a league of all his own.
As for him being a petty bully, I see a lot of politicians who are bullies. Even the Clintons and Obama are bullies and have used the power of government to go after their political enemies. The media narrative is that only Republicans are bullies, Nixon being the primary example. Yet Johnson and even Kennedy did more and got away with it, such as using the IRS to go after people they didn't like. So again, I see it as more of a media creation than anything, at least with all the publicity that it's receiving.
To your point that the individual directly responsible was supposed to have fallen on his sword, you may be correct on that, but it's hard to say. Who knows if the local newspapers or VOX or Salon would continue to stoke the flames? I could see it happening.