It doesn't even need to be a "mistake". My lab does MRIs of humans and animals. There's a crazy amount of variability in the structure and function of an alleg

It doesn't even need to be a "mistake". My lab does MRIs of humans and animals. There's a crazy amount of variability in the structure and function of an allegedly "normal" subject's brain. For example, a good friend has what looks like an extra little bump near the vertex. He's normal enough though, and will probably finish his PhD this year. The Brain Imaging Center does refer people with weird scans to (clinical) neurologists. They've caught a few things, but the vast majority of those are also "weird, but apparently fine" too.