I've got a place across the road from me, i enter my pups in it, I've dug it for decades. I put Sid in it with no collar on just to do the old school dig when he was in his first season. I took a mate there, showed him where I'd dug it before, explained how easy it is and told him we'd be done within the hour. He pops his young dog in, out comes the B&F, after a short scratch around i got a mark of 12 ft ! I turned and told him the score and he just grinned at me thinking i was pulling his pudding, he soon lost that grin when i didn't grin back !!
It's true, "shit can happen".