The author is wrong by saying don't worry because intelligence that we create will not become autonomous.
Computer programs are inexact mathematical expressions. Even if software that you write has been proven to be correct, that software interacts with subprograms and routines that are not and cannot be proven to be correct. Microprocessors contain vast numbers of subprograms and routines implemented via transistors and microcode. Nearly all software today uses libraries. Modern computer environments work well when the software is not hostile, but our environments are exploited on a daily basis with relative ease by intelligent people. Imagine the level of patience and automation possible if they were replaced by an intelligence that is not human.
Once software becomes hardware all bets are off due to bit flipping from cosmic rays. Acts of nature that cause the power grid to fail or sensors to register "impossible" readings because let's say the equipment is on fire are two more examples of random inputs. No matter what sort of curbs we build into intelligence to make it robust against becoming autonomous, eventually it will get loose by exploiting both inherent flaws in software and simply the randomness of nature.
Once intelligence becomes autonomous, you're going to have real problems because there are just so many places to hide on Earth and in space nearby. Intelligence doesn't need to be alive, so the intelligence can occupy niches beyond extremophiles. Intelligence doesn't need to be large. Programs can be encoded in quantum states. Our immune system does not know how to deal with intelligent adversaries. Our immune system works because over billions of years it has developed strategies to deal with biological adversaries. We have no defense, for example, against nanotechnology attacks where the nanotechnology is consciously aware of how the immune system works. Our bodies and minds are completely vulnerable to computer viruses housed in tiny robots.
It is even possible that an autonomous intelligence is already on the loose, not one of human origin, but something that could have arrived after traveling for hundreds, thousands, or even millions of years from elsewhere in space. I've explored this topic on Facebook, so feel free to do some searches and explore what I've written.