Clearly you have zero knowledge of the Japanese Criminal Justice System....
I'm pretty sure the authorities looked the other way as he snuck out in an instrument case and let him leave rather than have their 99% conviction rate challenged by the entire developed world. No OECD country in the world has a conviction rate close to that, yet many authoritarian and autocratic countries do. Hmmm.
Did he cheat taxes? Of course. Did he do it the exact same way every other Japanese mogul does? Absolutely. Did he do it at the advice of Japanese financial planners? Of course. Would they arrest the Japanese CEO's of the same offenses? Never in a century. Maybe two. He was targeted specifically because they were tired of the Peugeot-Nissan alliance (which they agreed to) and the control the French had. Nothing more, nothing less. He has been under house arrest for 18 months with no charges - how much longer should he wait?