Our shepherd can open our front door and security screen door because we have those long style handles you push down. He just paws them open and pushes or pulls the door. Unfortunately they are the kind tht are open in the house but locked on the outside. Sometimes he will walk up to the doors and let Raisin and himself out. Just last night I went chasing after them and shut door behind me locking all of us out (luckily I keep a spare).
So it could be possible the dogs open the door, or pushed it open if owner didn’t shut the door completely, or maybe someone open the door for unknown reasons (why someone would I don’t know, but strangers things have happened).
Either way its sad for the dogs, for the victims, and the owner. When we leave for work we put our dogs in their crates. I used to feel bad crating them but now I just tell them its for their own safety. I think the best thing we can do is continue being responsible owners. Getting our dogs out there and socializing them. Being a role model as not only a dog owner but a citizen in our communities. Most importantly learning from others mistakes so our pibbles can continue to have a good life.