For the interested; the saying I believe you are referencing in regards to writing code / debugging is from Brian Kernighan, specifically:

  Everyone knows that debugging is twice as hard as writing a program in the first place. So if you're as clever as you can be when you write it, how will you ever debug it?

It's prescient.

It’s a cute statement, but it doesn’t really match reality. Programs written by humans can generally be debugged by humans.

Could AI write programs that humans can’t understand or debug? Probably, but that’s not what Kernighan was describing.