The Department of Justice’s prosecution of Mark Forkner, the only Boeing employee charged with a crime after the two fatal crashes of the 737 Max, rested heavily on lengthy instant message exchanges with a Boeing colleague. His documented remarks were by turns profane and insulting, and deeply shocking when made public. The most damning suggested that he knew about a design change Boeing made late in the program to the jet’s new flight control system — a critical change that he was accused of hiding. Yet his trial ended swiftly after less than four days. With just one defense witness testifyin…