Something something Dunning-Kruger Effect. Dumb people who know very little about a topic will tend to overestimate their knowledge about said topic. As you gain more knowledge about the topic, the more you realize you don’t know, and the less confident you are about it.
In extreme cases, it ends with the person having Imposter Syndrome. When a person is very knowledgeable and experienced in a certain topic, but believes they aren’t qualified enough to be considered an expert. They feel like an imposter who will inevitably get outed by someone more knowledgeable than they are. So they have a lot of anxiety about speaking on the topic, because they’re afraid it will result in them being outed as an imposter.
He’s cooked.
For the unaware, Japan has like a 99.9% conviction rate after arrests, because they basically don’t arrest unless they’re absolutely 100% positive that they can secure a conviction. The suspect also has no right to an attorney, and police abuse is common; Even if you’re innocent, they’ll just keep you in an interrogation room without any food or water for 72 hours until you “confess”. They’ll literally just rotate cops into the interrogation room, without giving you a break for food or sleep.
And Japanese prisons are some of the strictest. You’re basically expected to remain silent, and every moment of your time is accounted for. You get like 20 minutes to eat each meal (in your cell) and then like 30 minutes of “recreational” time outside, where you’re expected to kneel in place in an empty courtyard. Moving to and from your cell is akin to old elementary schools where everyone would have to line up single file and silently walk from one place to the next while following the teacher. And that’s pretty much your daily routine for the entire time you’re in. You sit in your cell, slam down what little food you get, silently walk to the courtyard, silently kneel for 30 minutes, silently walk back to your cell, and slam down dinner before bedtime. Any deviation is dealt with swiftly and violently by the guards.
Japan has a very skewed idea of criminal justice, because the prevailing attitude is that if you’re in prison, you must have done something to deserve it. It’s sort of a cyclical problem, where their insanely high conviction rate means that the public already assumes suspects are guilty before they have even been convicted.