I like this. Trump is not going to taked any cr@p from the GOPe it he thinks he has been wronged by them. Trump is a fighter and I like that.
In this case, it isn't the GOPe that is dealing cr@p to Trump. It's his own campaign's unfamiliarity with the particular state's rules of procedure. The Cruz organization took advantage of their deficiency...
There is no basis for a lawsuit. And threatening one probably harms Trump's standing with the rest of the Louisiana delegates.
Playing the bully may work for Trump in some venues. But it may be counter-productive when it comes to herding delegates.