NEED HELP - Digging Dog - What's Best Way To Stop?

My neighbor has a monster sized pitt bull that loved to dig under the fence to come over and play with my female shepherd until they passed out in their water bowls, but he got tired of his dog digging so he ran one of those bare wire electric cables about 6" from ground level and 3" away from the fence.
It did not take long for him to learn, maybe one or two jolts and ever since he will just sit two or three feet away from the fence and whine when he see's me or wishes he could play with my dog.
ZThe owner felt bad he could not play with my dog so he went out and got a mutt lab mix pup to play with and they have a good time.