Two systems that produce the same output for some set of inputs doesn't show the systems are the same. My phone can produce the same results as my brain for short arithmetic problems. My phone is not a brain.
The neuroscientists I know in the field would be among the first to tell you that our ability to model the brain is nearly non existent. In fact we don't even have a great model of a single neuron [1]. This statement doesn't invalidate the work folks are doing to try and reach that goal. Biology is hard.