Well then you can move the dead mouse on tongs so that it is moving....
or convert it.
When I first started keeping snakes in the 90s I belonged to a herp club. One of the members kept a huge variety of wild caught local snakes for educational purposes, he had black racers, eastern milks, eastern kings, eastern hoggies and water snakes and every single one of them ate f/t prey. He had this one snake, a dog tame black racer named "one eyed Jack" because somehow he lost an eye before Bob caught him. He was the coolest thing, and ate f/ted like it was going out of style!! Bob told me he tamed him by letting him bite until he was tired and slowly realized that humans were not a danger to him.
And you know, it is perfectly LEGAL to do anything to a feeder animal. But what he is doing is cruel and wrong and sick. You say that a news story wouldn't hurt him, because he sells so many cool things but most people don't own animals like this, and would not be impressed with all his "cool stuff".
Imagine on a slow news day....headlining the 6pm news...."This man's actions are so disturbing that even his peers are speaking out against it". Followed by an in depth report of the allegations, complete with undercover camera recordings of what he does, complete with the mouse squealing in agony. Complete with interviews of other herp keepers "in the know" talking about the humane way their feeder mice are treated. Are you quite certain that this would not hurt him?