He was doing the typical shooting off the mouth routine that's become the norm for a member of a minority when it's time to gracefully bow out. Again, IMO.
That's being overly generous. It merely shows that his legal position was so weak that even Gloria Allred had doubts that they could successfully extort a payoff from the city council and mayor. I thought Allred and Parks would try anyway.
Given Parks' surprising decision not to sue, his early resignation makes sense. For one thing, by forcing the city to scramble for an interim chief and speed up its selection timetable, it is a tiny bit of payback. (While it's amusing to contemplate the thought of suing Parks for breach of contract, from a political viewpoint it's absurd. After Los Angeles had unequivocally repudiated Parks' leadership, to say the city needs him so much it is willing to sue to keep him on the job for another four months would make a laughingstock out of city officials. And they're a big enough laughingstock as it is.) For another thing, Parks is trying to play the role of noble victim, leaving with his dignity intact so he can fight again some other day rather than being dragged out kicking and whinging.
If Parks had accepted the original decision with a stiff upper lip, that might have been evidence of character. This is just politics.