The Audya is a rock solid piece of hardware and has served musicians well 7 nights a week 52 weeks a year for over 10 years now.
It is IMPOSSIBLE for the Audya to reset to factory settings on its own...100% impossible. Why you might ask? Because virtually everything is saved and stored on the hard drive just like your laptop, not in ROM like the old fashioned keyboards were.
So what could have happened?
Hard drives/SSD's fail sometimes, its nobody's fault...it just happens which is why we all keep back ups of our data, wether its a laptop, phone or keyboard. There is also the possibility he accidentally formatted the hard drive if he was careless when formatting a USB stick. Its not easy to do, with multiple warnings on the way...but people ignore them (I am amazed how often people do this).
Anyway on a more constructive note your friend can do some simple checks HERE
Your welcome to post back here with the results, but I cant guarantee a reply quickly as I only call by from time to time. Your friend might want to call his distributor with any information he gets from the above.