Never said it was safe, I said that it was minimal risk from my own experiences with my own collection and the number of times that I've even had one get a small scratch.
Frozen/thawed also has its risks if someone does not properly defrost a prey item and it rots in the belly instead.
However - it's up to each individual keeper to make their own educated decision as to what works best for them. For me, live works best, and I have no compelling reason or desire to switch to f/t for my ball pythons.