If we look at it from a purely technical standpoint, every event (no matter how unique) has to follow the laws of physics (or the laws of nature, but probably for aviation it is 99% physics). All of them can be translated into formula and constants. For all things that can happen, there is a sort of sensor available which would detect it. So If you can have a computer that can do any calculation of any natural law (is unbelieveable powerful and quick), and has all sensors wired to it which could detect any parameter existing around, then yes, a computer can deal with any event.
but...
We all know, that the more complex a system gets, the more sensors you have, the more bugs are in, the more failure happens, the more false information is gathered, which would then also result in wrong decisions taken.
So with every additional aspect we would consider in the system (to make sure we are able to deal with whatever is physically possible) we would increase the number of bugs and sources for failure. At a certain level, the event we want to prevent is less probable than a malfunction of the system we install to deal with it.
Thinking of real MTBF figures of existing components, which sometimes (for whatever reason, most probably cost...) are as low as 1000 FH, it would not make the aircraft safer for any event what is unique enough to happen only every 1000 FH. Of course we can significantly increase reliability figures by installing redundancy, but we will always have a finite reliability of the system, hence we have a certain probability of events for which the risk of it to happen is lower, than the risk of the system dealing with it to fail.
therefore:
practically we will never be able to create systems which can deal with every unique event, which would not result in system failures causing accidents at a rate in the same order of magnitude as the unique event we wanted to deal with.
Which also is true for pilots, we can never train them good enough for any unique event that may happen, they will always make mistakes and errors (which would be another interesting philosophical discussion, whether pilot error or pilot mistakes are the real issue...) in an order of magnitude higher than very unique events.
But slast is absolutely correct, instead of looking at statistics of very, very rare events, we should look at statistics of the billions of correct decisions taken, correct actions performed and flight hours of systems doing exactly what they should. We should not try to avoid something vary rare, by taking responsibility from those who do something right 99.99999% of the time. We should try to support those doing a good job to make a perfect job (humans and systems). We should check who is doing what best, and then support him / improve it.