I don't know what "that" was, and again, I had both the vaccination and the digital certificate to prove it; the system in place would not accept the real documents, so I fed it with other documents that it did accept.
Eventually in a system like that they may refine their procedures and then you get dinged essentially...
"The guy who went to jail" could be unvaccinated (or even infected) and presenting other people's certificates to enter an area for vaccinated people only (e.g. hospitals) where he might have endangered other people's lives; that's something that might be deserving jail time. I was vaccinated however, and by all means had the right to enter that shopping mall; I just wasn't able to prove it to the imperfect system that was there to check.