Well, selective justice is a form of injustice. I only have superficial knowledge of the Ghosn saga, but if what the GP alleges is true, then it's not fair to Ghosn that he's prosecuted for something that others get a pass. Of course, I take your point that it's entirely possible to be a bigcorp CEO without fraud and self-dealing.
To scale it down, lots of people drive over the speed limit, which is against the law; but only some people get pulled over and ticketed for it. Many people also observe the speed limit. In the Ghosn analogy, suppose that Japanese drivers got a pass, but foreigners didn't.
Should everyone get pulled over the instant they exceed the speed limit? Do we want to live in such a world? Is it just a matter of scale, the difference between driving a car too fast vs. stealing millions of dollars from your employer?