[Kirby's Dad]

That is complete nonsense that we teach them to dig, it's instinct. They bury bones to hide them, much like squirrels hoard nuts. They dig to find bugs and other things to eat, they dig to make a soft place to bed down and to escape confinement etc...

As someone else suggested, I think I would change trainers, I would question that trainers understanding of dog psychology which I would think would be pretty important in training dogs.