If the witch in question were a real witch, he or she should have been able to stop the flames and walk away, unharmed.

However, as the majority of witches burnt were burnt only so a neighbour could have their land, it is safe to say that they could not have succeeded with said trick.

Also, never burn a witch that you've just dunked. It's like trying to burn a wet log.

For some reason "Natasta" springs to mind, too.