From the beginning, Ghosn has employed a team of publicists to manage his image during the arrest and trial. Their primary focuses have been on highlighting the injustices of the legal system in Japan and on portraying an apparent conspiracy against Ghosn perpetuated by Nissan and the Japanese government. It's not hard to see how successful they've been in getting support for Ghosn.
Meanwhile, this strategy has successfully shifted focus away from the charges themselves - charges that include Ghosn secretly shifting $5 million from Nissan to companies his wife and son own in Lebanon.
One point that is interesting in hindsight is that Ghosn decried the injustice of not receiving bail in January, when prosecutors successfully argued that he was a flight risk. He received it in March with heavy restrictions.
In hindsight, the strategy of managing his image, promoting a conspiracy, and denouncing injustice, all while diverting attention away from the charges, seems built with the intended outcome of him fleeing the country. Of course, it probably wasn't planned that way, but it's certainly better to flee and rebuild your life when international public opinion is in support of you rather than against.
In any event, the likely outcome now is that we will never find out the truth behind the four charges against Ghosn.