I talked to a woman that worked where Bandit got neutered. I asked about that spot that looked burned. That is exactly what they do. They knock them out ( I hope) and cauterize them. Its cruel IMO. And seems to me like it could be very possible that some tissue is left behind. If you ever need an animal broken make sure you ask how they do it.
What? That's weird. Never heard of that. At the clinic I worked at we knocked them out, shaved the scrotum and made an incision down the middle. Then one at a time pop a testicle out clamp, cut and tie it off. Then stitch or glue the incision back together. We also sent pain meds home to use the next day because they got a shot of it while under.