Our Bedlington Terrier was a resource guarder on par with that dog. We had him 15 years, starting when I was 10. He had exactly one bite, and it was someone who didn't know him (he got a...used personal hygiene product...out of the trash can, and she tried to grab it back from him). One bite in 15 years. Because when he had something he was allowed to have, but guarded, we left him the heck alone. And when he got something he wasn't allowed to have, we traded him.
We probably could have trained it out of him if we'd known better. But we simply found an easy way we could all live with it, and everyone was fine. It isn't rocket science.
Would I have that dog in the house with a toddler? Probably not. But they had an infant, right? So a year or so in which they could have done the training before the kid was really mobile and it was going to be an issue. My friend took in a dog for evaluation from the humane society, because the dog was resource guarding. Darn if within about 3 weeks, that dog wasn't picking up everything she could find and carrying it to whichever person was closest, in hopes that they would please please offer to trade with her for a cookie. Shoes. Toys. Socks. Anything on the floor, she'd carry up to you, parade back and forth, shoving it in your lap and woo-wooing.
Again, not rocket science.