My experience with testing avionics controllers was: Everyone seemed to have the correct idea (that bugs were basically Not Allowed.) The company set up enough testing so that those bugs were eventually eliminated. However, the difference between good projects and bad projects was mostly the amount of time and money that this took.
My favorite was one where we had an entire test harness written in Python that could completely control the operation of the device being tested in a way that resembled human input. Code was first written in Ada against a monolithic requirements document, while testers wrote their standard test cases against the same document. After the exhaustive amount of testing that took place by developers, testers themselves had the freedom to create contrived test cases that might have escaped the attention of devs (What if we just turn the machine on and off 10 times, because why not?).
This had the advantages of a formal software process as well as the ability to exploit human creativity. It also led to me losing a bet that a doppler radar can't be fooled with an empty potato chip bag.
My wild guess loosely based on my time spent writing software to analyze observed radar signals: I believe the parent probably opened the bag along the seams to get one flat piece of reflective (on the inside of the bag) material. I know weather balloons are often reflective so they can be tracked by radar. I'm guessing a full-size potato chip bag opened flat would be big enough for the radar to see, couldn't tell you if that's what the parent meant by fooling the radar or if something else was done to the bag to make the radar interpret it as an aircraft.
My favorite was one where we had an entire test harness written in Python that could completely control the operation of the device being tested in a way that resembled human input. Code was first written in Ada against a monolithic requirements document, while testers wrote their standard test cases against the same document. After the exhaustive amount of testing that took place by developers, testers themselves had the freedom to create contrived test cases that might have escaped the attention of devs (What if we just turn the machine on and off 10 times, because why not?).
This had the advantages of a formal software process as well as the ability to exploit human creativity. It also led to me losing a bet that a doppler radar can't be fooled with an empty potato chip bag.