That’s the owners own fault for leaving the batteries laying out. Batteries should be stored like any other flammable material.
And it was a cell phone portable charger.
Laptops use LiPo batteries. So the dogs could have chewed the corners off a laptop.
By the looks of the place the dogs run the show and the owners give them the run of the house. I am a firm believer if you don’t exercise a dog, they will find a way to discharge their energy by chewing up your house. A well-trained dog that is exercised regularly won’t chew up your stuff.