The difference is if an AI fails to handle a certain situation then it will fail every single time. With humans there is a random element and a small fraction end up failing.
But to an AI, a certain situation has millions of data points, it's very rare for a certain situation to reoccur. Similar types and classes of situations? You betcha. But they'd be handled based on other data points as well.
Then it's not an AI but just complicated if-statements; if it was more like a real AI then it would learn from the experience. The core premise of AI is that it's learning and improving all the time, not that it does the exact same thing every time.
you don't want that either, because you want to quality control the changes to behaviour. see for example first generation Forza drivatars, that learned from other online player unconstrained and became insufferable assholes
But situations are never "the same". The input (camera images, sensor data) will always be (slightly) different and – in this example – might just lift the confidence of "this is a truck standing on the road" over the threshold.
In practice Tesla's thing only seems to have crashed into a fire truck a couple of times against I imagine a large number of misses.