Other aspects weren't 100%, such as identifying the severity (which was around 70%).

But if I gave a model pictures of dogs and traffic lights, I'd not at all be surprised if that model had a 100% success rate at determining if a test image was a dog or a traffic light.

And in the paper they discuss some of the prior research around biological differences between ASD and TD ocular development.

Replication would be nice and I'm a bit skeptical about their choice to use age-specific models given the sample size, but nothing about this so far seems particularly unlikely to continue to show similar results.