We can, but the nice thing about neural networks is the ability to do all kinds of computational and mathematical manipulations to them to basically pick them apart and really find out what’s going on. This is important not just for safe deployment but also for research on new methods that could be used to make them better. Plus we need this ability to help avoid neural networks with intentionally hidden features that appear to behave linearly in certain regimes but are designed with a strong nonlinear response when special inputs are applied. You could have all the tests you want for a self driving car based on real world conditions but some bad actor with access to the training system could create a special input that results in dangerous behavior.