[gamblor956]

claiming AI (used as a search tool) as an illegitimate cause for the warrant is a ploy by the defence

The problem here is the same as if the police had coached a witness to identify a pre-selected suspect. The police had already decided that Tolbert was their suspect (albeit without knowing his name) by the time they ran his image through the AI facial recognition, so they discarded all the other matches.

The court also noted that AI facial recognition is no different from an "anonymous informant," which cannot be used to establish probable cause under Ohio law because, very crucially, it can't be questioned under oath.

it doesn't seem like natural justice or any broader rights would be served by letting this guy off

This assumes that the suspect was actually the killer. We don't know if Tolbert was the killer because the police the police conducted a bare-bones sham of an investigation, and lied about how they conducted the investigation in court. They could easily be wrong about the killer's identify, which means they would not only be putting an innocent man in prison, but also that the true killer would still be free and in a position to murder more people.