Not quite. Another popular example is the cnn learning to distinguish wolves from non-wolves, because the wolf was always photographed on snow & the other anima

Not quite. Another popular example is the cnn learning to distinguish wolves from non-wolves, because the wolf was always photographed on snow & the other animals not on snow. It just learnt to distinguish snow vs non-snow instead of wolf vs non-wolf. It then failed catastrophically when you put a non-wolf on snow. There's no leakage in either case. The model is learning one thing and you think it's learning another.