I may not be a trainer but I have house broken several dogs with no problems.

This is how I do it...

Keep the dog in the crate. (but make sure he gets play time too!).
Take pup out on a leash. Wait him out even if it takes 30 mins. If he don't go, don't yell or punnish the dog. Just put him back into his crate, wait 10 mins and take him out again. If he still won't go just keep doing this. It may take a while but he will go. Once he does go praise him tons and tons and play with him. Like said above.
Also when outside tell them "Do not let him wander around. Keep him on a short leash and just stand in one place. Other wise he will just explore as much as they let him.

After he goes they can keep him tied to themselves so they can make sure there are no accidents.


As for the crate use a small one(depending on the size of the pup), they can't have a lot of room or they will go in it.
They may just have to retrain him from the start.
I hope I helped Like I said I'm no professional but thats how I housebreak pups and older dogs.

I wonder if the owners are yelling at him for peeing on the floor and scaring him? Thats what it sounds like to me. Of course I don't know the whole story, but it's odd that he hides under the couch and bites at the owner when he/she reaches for him.