J.T. Washi comments

Not saying that he was intoxicated, but IF he was, perhaps the employee followed him out to see if he was heading to a taxi or his own vehicle.

A lot of people mentioned why no one stopped him. He immediately ran to another platform and hopped on that train. People were focused on the victim who was almost killed! Those on the other platform may have noticed a commotion, but wouldn't have known what happened. Some of the commenters asked why his photo wasn't posted and that they hope he gets caught. He did get caught. It happened at 5pm Sunday...he was caught that very evening.

From what I understand, all it contains is the name of the person, where their local city hall is, and a contact number to that city hall. This prevents any identity theft. It just gives you their name and city. One would then contact the city for their residence and contact numbers. Easier for police or hospitals to do than someone just trying to get more info on someone. Also, anyone with a smart phone can check the code this way as opposed to prints. Dementia subject walks into your shop confused? You scan their code and contact their city hall. City hall contacts family and police. Police take subject home. Once more people who need this start using them, people in general will know what to look for. It's similar to how many people will write a dementia subjects name and address on their clothing, but this gives more privacy and safety. Plus, going through city halls leaves a 'paper trail'. If someone with dementia wanders off frequently and is brought home using this, it can alert social services to check up on their situation.

This issue isn't that the Japanese can't tell that foreigners with tattoos aren't yakuza, it's that you can't say "Oh, you have a tattoo/s and it's ok that you come here" and then say to someone with a tattoo (yakuza) that they can't. It's an all or nothing sort of thing.