If the car hasn’t been chipped or altered in any other way (electronically) by anyone other than Audi then it’s Audi’s job to put it right, assuming it’s still under warranty? Don’t take that no courtesy car crap either.
Fair play to the technician having a ‘quiet word’ with you though, dealers have a habit of re-flashing your ECU back to stock if you have had it modified within it’s warranty period. I guess he was giving you the option of saying ‘don’t worry about it, leave it as it is’, i.e. it is chipped and I don’t want you to reset it.
Audi A3 1.9TDI Sport Quattro