I think that this person does not know what the Jevons Paradox is. The Jevons Paradox is that increasing the efficiency with which a resource is used may increase the total amount of that resource that is used. Consuming more because costs went down isn't the Jevons paradox - it's spending more because costs went down.

So if you give all your coders a great test harness and they run more tests because it takes up less of their time, that's not the Jevons paradox. If you give your coders a great test harness and then they go from spending 10% of work hours on testing to spending 20% of work hours on testing because testing has such a good ROI now, that's the Jevons paradox.